[FAM3]

Hey guys!

I just recently got my 335is a few months ago. Just hit 4000 miles and have been doing exterior mods up until this point. I am coming from an e46 M3 so to be finally able to have a turbo engine such as the N54 is very exciting to me.

So my 335is is a 2012 and I LEASED it in stick (no hate on DCT but I love 6MT and cannot live without it.) Since it is a lease I will not be going INSANE with engine mods but obviously enough to be able to simply take on and off parts when needed.

The only "engine" mods I have thus far is the BMS DCI. I want to be able to mod the engine more in order to tune it with JB4, a simple plug and play.

I have been hearing multiple things from different people that say before I even get JB4 (or any tune) I should get a charge pipe with a BOV or a Diverter valve setup. If I do not have my engine properly ready for it many problems could arrise such as check engines, etc...I def want to try to avoid that.

Is this true? I mean I understand the stock charge pipe may not be able to hold a lot of boost from JB4 but is there not a map where it is made to work with a relatively stock setup? Is a chargepipe a necessity for this car if I plan on tuning it? What is a necessity for the car if I plan on tuning it?

Next up is the exhaust/tone of the car. Don't get me wrong I love the way the 335is exhaust sounds but I feel it needs to be a bit louder. A lot of people on the forums have said the true way to get a better tone from this car is to install downpipes. I have done my research and I believe that the AR Design downpipes would be best suited for me. Any opinions on downpipes? Any lease people on here that have ever had any issues with downpipes throwing codes, etc?

Should I be installing the chargepipe and downpipes before tuning? What is the correct way to go about this? Is there an order that needs to be followed? Sorry I am a new at modding a turbo car so I ask these questions to learn from you guys!

Thanks!

[benzy89]

The OEM Charge Pipe + Diverter Valves are "hit or miss" with most people. Some people get lucky and get run 18 lbs of boost and never experience a leak, some people go to run 12 psi and they break or crack and then start leaking. The main reason why most people switch to an aftermarket CP + DVs/BOV is because they decide to run meth. It's your car so it's your call whether or not you want to run meth. If you decide to, running meth from the Windshield Washer tank as meth tank will be the easiest way to do it (if you take your car for service covered by the lease, meth would probably start a fight with a Service Dept).
**Warning -- Some forum users have experienced engine bay fires caused by leaks in the WW tank or piping. What happens is meth (flammable fluid) leaks onto a hot engine & ignites. Your call on this one, a meth system can easily be run from the tank but the wiring/piping to the engine bay may require some lease-voiding modifications to the car.

Downpipes will have a substantial impact on your exhaust. Because you have a 335is, you already have the BMW Performance exhaust installed on your car, so going to catless DPs will not only give you a quality exhaust note, but will also give substantial performance gains. There are several DP brands that are worth going with:

1. AR Design -- The most expensive option I'll list, but possibly the most popular DP. Supposedly is the best fitting DP.
2. cP-E -- Quality DP company, makes both Catless & Race-Cat DPs for both the RWD + AWD 335s
3. Macht Schnell -- Another quality company, a nice middle ground on price between AR + VRSF
4. VRSF -- The least expensive DP option. Some people find these to be as good as ARs for 1/2 the price.

If it matters to you, AR, cP-E + Macht Schnell all offer ceramic coating on their DPs when you buy new. This would obviously increase cost, but will also increase re-sale value (if you decide to buy any of these brand new) when you go to sell them after your lease ends.


Any "mod" friendly dealer will have no problems with DPs being installed & unless the car is up on a lift, they probably won't even notice.

Upgrading your DPs isn't a very difficult or a non-reversible modification. While it's not as easy as changing the intake, if you have a good mechanical sense + rhino ramps or jacks, you can do a DP install in your driveway. I have Akrapovic DPs in right now, but am keeping my OEM DPs in case I ever need them for a "sniffer" emissions testing. If you're not planning on keeping your DPs, try to find some used ARs or just buy a set of cP-e, Macht Schnell or VRSFs. Don't be fooled that b/c VRSFs are the least expensive, that the quality is subpar. This might be a bold statement, but the VRSFs are probably the second most popular DPs to the ARs.

As for fault codes, all of the major tunes (JB4, PROcede or COBB) cancel out the emission codes caused by going catless. It's your call which tune to go with & I'm not going to start a "Which tune is best" war, but it sounds like the COBB might be the best tune to go with in your case since you will never have to open to hood to flash for different performance settings. The PROcede or JB4 are not difficult to install/uninstall by any means, but can be a little intimidating to someone not technically-savvy or unfamiliar with the car. The COBB also is the easiest to data log with (to make sure your car is responding well to the mods & is able to run the performance setting without doing any damage to the car) and read any fault codes that get triggered.

The first performance mod should always be a tune, followed by an intake, then either meth, DPs or a FMIC. In your case, an FMIC might not be an option since there is trimming for any aftermarket FMIC (even with 5" cores, there is very very little trimming, but on a leased car you can't really cut anything with a dremel) and meth is obvious and would not sit well with the Dealer Service Dept. For you, a tune, intake + DPs will probably be the best modifications to make that will yield a substantial increase in performance without voiding your warranty.

You're welcome in advance, I got a laugh out of this thread a few weeks ago when I tried to sell you my VRSF DPs and you said you had no interest in upgrading from the OEM one's

[e1001usa]

Originally Posted by benzy89

The OEM Charge Pipe + Diverter Valves are "hit or miss" with most people. Some people get lucky and get run 18 lbs of boost and never experience a leak, some people go to run 12 psi and they break or crack and then start leaking. The main reason why most people switch to an aftermarket CP + DVs/BOV is because they decide to run meth. It's your car so it's your call whether or not you want to run meth. If you decide to, running meth from the Windshield Washer tank as meth tank will be the easiest way to do it (if you take your car for service covered by the lease, meth would probably start a fight with a Service Dept).
[COLOR="Red"]**Warning[/COLOR] -- Some forum users have experienced engine bay fires caused by leaks in the WW tank or piping. What happens is meth (flammable fluid) leaks onto a hot engine & ignites. Your call on this one, a meth system can easily be run from the tank but the wiring/piping to the engine bay may require some lease-voiding modifications to the car.

Downpipes will have a substantial impact on your exhaust. Because you have a 335is, you already have the BMW Performance exhaust installed on your car, so going to catless DPs will not only give you a quality exhaust note, but will also give substantial performance gains. There are several DP brands that are worth going with:

1. AR Design -- The most expensive option I'll list, but possibly the most popular DP. Supposedly is the best fitting DP.
2. cP-E -- Quality DP company, makes both Catless & Race-Cat DPs for both the RWD + AWD 335s
3. Macht Schnell -- Another quality company, a nice middle ground on price between AR + VRSF
4. VRSF -- The least expensive DP option. Some people find these to be as good as ARs for 1/2 the price.

If it matters to you, AR, cP-E + Macht Schnell all offer ceramic coating on their DPs when you buy new. This would obviously increase cost, but will also increase re-sale value (if you decide to buy any of these brand new) when you go to sell them after your lease ends.


Any "mod" friendly dealer will have no problems with DPs being installed & unless the car is up on a lift, they probably won't even notice.

Upgrading your DPs isn't a very difficult or a non-reversible modification. While it's not as easy as changing the intake, if you have a good mechanical sense + rhino ramps or jacks, you can do a DP install in your driveway. I have Akrapovic DPs in right now, but am keeping my OEM DPs in case I ever need them for a "sniffer" emissions testing. If you're not planning on keeping your DPs, try to find some used ARs or just buy a set of cP-e, Macht Schnell or VRSFs. Don't be fooled that b/c VRSFs are the least expensive, that the quality is subpar. This might be a bold statement, but the VRSFs are probably the second most popular DPs to the ARs.

As for fault codes, all of the major tunes (JB4, PROcede or COBB) cancel out the emission codes caused by going catless. It's your call which tune to go with & I'm not going to start a "Which tune is best" war, but it sounds like the COBB might be the best tune to go with in your case since you will never have to open to hood to flash for different performance settings. The PROcede or JB4 are not difficult to install/uninstall by any means, but can be a little intimidating to someone not technically-savvy or unfamiliar with the car. The COBB also is the easiest to data log with (to make sure your car is responding well to the mods & is able to run the performance setting without doing any damage to the car) and read any fault codes that get triggered.

The first performance mod should always be a tune, followed by an intake, then either meth, DPs or a FMIC. In your case, an FMIC might not be an option since there is trimming for any aftermarket FMIC (even with 5" cores, there is very very little trimming, but on a leased car you can't really cut anything with a dremel) and meth is obvious and would not sit well with the Dealer Service Dept. For you, a tune, intake + DPs will probably be the best modifications to make that will yield a substantial increase in performance without voiding your warranty.

You're welcome in advance, I got a laugh out of this thread a few weeks ago when I tried to sell you my VRSF DPs and you said you had no interest in upgrading from the OEM one's

Nice write up

[FAM3]

Originally Posted by benzy89

The OEM Charge Pipe + Diverter Valves are "hit or miss" with most people. Some people get lucky and get run 18 lbs of boost and never experience a leak, some people go to run 12 psi and they break or crack and then start leaking. The main reason why most people switch to an aftermarket CP + DVs/BOV is because they decide to run meth. It's your car so it's your call whether or not you want to run meth. If you decide to, running meth from the Windshield Washer tank as meth tank will be the easiest way to do it (if you take your car for service covered by the lease, meth would probably start a fight with a Service Dept).
**Warning -- Some forum users have experienced engine bay fires caused by leaks in the WW tank or piping. What happens is meth (flammable fluid) leaks onto a hot engine & ignites. Your call on this one, a meth system can easily be run from the tank but the wiring/piping to the engine bay may require some lease-voiding modifications to the car.

Downpipes will have a substantial impact on your exhaust. Because you have a 335is, you already have the BMW Performance exhaust installed on your car, so going to catless DPs will not only give you a quality exhaust note, but will also give substantial performance gains. There are several DP brands that are worth going with:

1. AR Design -- The most expensive option I'll list, but possibly the most popular DP. Supposedly is the best fitting DP.
2. cP-E -- Quality DP company, makes both Catless & Race-Cat DPs for both the RWD + AWD 335s
3. Macht Schnell -- Another quality company, a nice middle ground on price between AR + VRSF
4. VRSF -- The least expensive DP option. Some people find these to be as good as ARs for 1/2 the price.

If it matters to you, AR, cP-E + Macht Schnell all offer ceramic coating on their DPs when you buy new. This would obviously increase cost, but will also increase re-sale value (if you decide to buy any of these brand new) when you go to sell them after your lease ends.


Any "mod" friendly dealer will have no problems with DPs being installed & unless the car is up on a lift, they probably won't even notice.

Upgrading your DPs isn't a very difficult or a non-reversible modification. While it's not as easy as changing the intake, if you have a good mechanical sense + rhino ramps or jacks, you can do a DP install in your driveway. I have Akrapovic DPs in right now, but am keeping my OEM DPs in case I ever need them for a "sniffer" emissions testing. If you're not planning on keeping your DPs, try to find some used ARs or just buy a set of cP-e, Macht Schnell or VRSFs. Don't be fooled that b/c VRSFs are the least expensive, that the quality is subpar. This might be a bold statement, but the VRSFs are probably the second most popular DPs to the ARs.

As for fault codes, all of the major tunes (JB4, PROcede or COBB) cancel out the emission codes caused by going catless. It's your call which tune to go with & I'm not going to start a "Which tune is best" war, but it sounds like the COBB might be the best tune to go with in your case since you will never have to open to hood to flash for different performance settings. The PROcede or JB4 are not difficult to install/uninstall by any means, but can be a little intimidating to someone not technically-savvy or unfamiliar with the car. The COBB also is the easiest to data log with (to make sure your car is responding well to the mods & is able to run the performance setting without doing any damage to the car) and read any fault codes that get triggered.

The first performance mod should always be a tune, followed by an intake, then either meth, DPs or a FMIC. In your case, an FMIC might not be an option since there is trimming for any aftermarket FMIC (even with 5" cores, there is very very little trimming, but on a leased car you can't really cut anything with a dremel) and meth is obvious and would not sit well with the Dealer Service Dept. For you, a tune, intake + DPs will probably be the best modifications to make that will yield a substantial increase in performance without voiding your warranty.

You're welcome in advance, I got a laugh out of this thread a few weeks ago when I tried to sell you my VRSF DPs and you said you had no interest in upgrading from the OEM one's

First of all thank you SO MUCH for taking the time to write this through answer. You have really helped me out with this information and I GREATLY appreciate it! So I already installed BMS DCI and that alone is an "intake for me" don't think I will go any crazy AFE setup since from reviews intake does not help this car much. I agree no FMIC i do not want to have the cut anything. I will not be going meth setup at all so no worries there. I do want to run a Charge pipe though, it would save me the headache of having to fix the stock one if it ever broke. Any recommendations on what setup? DV or BOV? What brand has good resell/performance just like DP's, etc...

JB4 is all I know because it is so common and I actually have installed it before for a friend so if the only downside is the install then that is not too bad. Why do you recommend Cobb so much? Isnt the JB4 also easy to use from the steering wheel so I "will never have to open to hood to flash for different performance settings"? How is Cobb setup? So regardless all of these tunes will take care of codes being thrown up.

Next up sorry I didn't pick up your VRSF DPs it was just I am stuck on AR Downpipes due to Yondaime (another user here) who showed me a video clip of his stock 335is exhaust with the AR DP setup. Sounded amazing and just what I would like. I read many reviews as I have stated and AR design seems to be very popular with little to no fitment issues which is a BIG + for me. By no means did I mean to disrespect you selling your VRSF DPs it is just I had a WTB thread for AR DP's and no other brand. I was just not on the hunt for those DPs in particular

But regardless I was worried about DP's being a problem at the dealer but I mean if something goes wrong with the car very badly I will just take them off and bring the car in for service I know it is a pain but it is a must for this situation.

[psmitty95]

Originally Posted by texxy

First of all thank you SO MUCH for taking the time to write this through answer. You have really helped me out with this information and I GREATLY appreciate it! So I already installed BMS DCI and that alone is an "intake for me" don't think I will go any crazy AFE setup since from reviews intake does not help this car much. I agree no FMIC i do not want to have the cut anything. I will not be going meth setup at all so no worries there. I do want to run a Charge pipe though, it would save me the headache of having to fix the stock one if it ever broke. Any recommendations on what setup? DV or BOV? What brand has good resell/performance just like DP's, etc...

JB4 is all I know because it is so common and I actually have installed it before for a friend so if the only downside is the install then that is not too bad. Why do you recommend Cobb so much? Isnt the JB4 also easy to use from the steering wheel so I "will never have to open to hood to flash for different performance settings"? How is Cobb setup? So regardless all of these tunes will take care of codes being thrown up.

Next up sorry I didn't pick up your VRSF DPs it was just I am stuck on AR Downpipes due to Yondaime (another user here) who showed me a video clip of his stock 335is exhaust with the AR DP setup. Sounded amazing and just what I would like. I read many reviews as I have stated and AR design seems to be very popular with little to no fitment issues which is a BIG + for me. By no means did I mean to disrespect you selling your VRSF DPs it is just I had a WTB thread for AR DP's and no other brand. I was just not on the hunt for those DPs in particular

But regardless I was worried about DP's being a problem at the dealer but I mean if something goes wrong with the car very badly I will just take them off and bring the car in for service I know it is a pain but it is a must for this situation.

I think all downpipes sound the same since they're basically just a straight pipe... I could be wrong since i don't even have downpipes yet but that's what i've heard.

In regards to the stock DV/CP I wouldn't do it unless you really need to. It's just another thing for the dealer to try to call you out for and void your warranty. I'm actually having issues with my dealer right now because they badly scratched my intake. Also my car has JB4 and Stett CAI only and i've ran E85 mixes on map 5 with no problem. I was probably somewhere around 15-16 PSI since it wasn't that large of a mix but i didn't log so i'm not 100% sure.

[benzy89]

Originally Posted by texxy

I do want to run a Charge pipe though, it would save me the headache of having to fix the stock one if it ever broke. Any recommendations on what setup? DV or BOV? What brand has good resell/performance just like DP's, etc...

Why do you recommend Cobb so much? Isnt the JB4 also easy to use from the steering wheel so I "will never have to open to hood to flash for different performance settings"? How is Cobb setup? So regardless all of these tunes will take care of codes being thrown up.

But regardless I was worried about DP's being a problem at the dealer but I mean if something goes wrong with the car very badly I will just take them off and bring the car in for service I know it is a pain but it is a must for this situation.

The BMS DCI (or any true DCI) is a great upgrade, and if an aftermarket intake manifold is ever released, I will probably go with either a DCI, a true CAI (like STETT) or the Injen intake (the aFe will have to get scrapped b/c it mounts in the factory location off of the intake manifold). If you want to upgrade your Charge Pipe + DVs/BOVs, and am somewhat conscious of resell value, I would recommend that you buy:

• Evolution Racewerks Charge Pipe -- Buy the Long Style Pipe, Anodized Black + with 1 Meth Bung. This is a more expensive combination, but go with the Long Pipe b/c it replaces all the plastic charge pipe elements (no weak point), Anodized Black b/c it's like a ceramic coating for DPs and at least 1 meth bung just b/c it'll increase resell value (you can leave the meth bung sealed since you won't use meth, but when you go to sell it it'll be more appealing to potential buyers)
• Forge Diverter Valves -- I went w/ DVs because I cannot stand the WHooosh noise of a BOV and I like that it recirculates the boost back into the intake tract, helping the turbos build up requested boost faster. The Forge DVs have a higher resell value then most BOVs due to rarity. The other benefit with the Forge DVs is they can be serviced very easily & inexpensively (you can buy a Forge service kit for $20). If you use a BOV and really beat on it, eventually it'll stop holding boost. BOVs can be serviced inexpensively, so you'll probably end up having to buy a new one ($$$).

I went with COBB because I really wanted a flash tune. Once either of the plug-in tunes are installed, you'll never have to open the hood again unless you're updating your firmware (if an update was released) or if you were removing it (you can switch maps right from the steering wheel). Another "selling" point of both the plug-in tunes is meth management (I wasn't running meth so this didn't matter to me). Nothing against BMS or Vishnu (great products from two great companies), but I wanted to make sure I wasn't going to sacrifice reliability for performance. With plug-in tunes, they intercept the signals being sent to the DME & then send a higher performance request signal back (creating an intermediary step). If the performance being requested was too aggressive & knock occurred, the plug-in tune wouldn't be able to correct timing/correct knock as quickly as a flash b/c of that extra step. SO from there I decided I wanted a flash tune, which left COBB & GIAC. I went with COBB because of their reputation with the time attack EVO, STi and most recently the GTR. COBB's highlights are you buy the AccessPORT & download the AP Manager Module onto your computer. You download the maps (corresponding to your mods installed & octane available) from the COBB website onto your computer + sync up to 100 maps onto the AP. Then you can just run out to your car, flash the DME for whatever map you want & enjoy. I really liked the idea of being able to have access to multiple maps (so I can use a reasonably powerful DD map & then after work flash for a higher performance setting). I also liked the in-depth monitoring, data logging capabilities & ease of reading fault codes (it helped me diagnose that my DPs were installed incorrectly & which cylinders I was getting misfires from). ATR + ProTuning Maps recently came out, which really allows you to take advantage of the specific mods that you have installed (while there isn't too much difference between DPs, different FMICs performance very differently than each other -- between pressure drops & IAT suppression) & also maximize the gains of running E85 or Race Gas.

DPs really shouldn't cause any problem for your car & ironically enough, running an overly aggressive tune on the OEM DPs will do more damage than any of the aftermarket options. Since aftermarket DPs have less restrictive airflow, they will not only put less stress on the turbos but will also allow them to spool up faster. If for whatever reason you did get wastegate rattle or broke a turbo, you can switch right back to the OEM DPs, clear your codes + hobble your way over to a dealer.

Like 98.5% of the users on this forum, it sounds like you wanted the same thing I was going for: a modified, higher performance 335 without diminishing the reliability of the vehicle. Since your car is a lease, I can completely understand why you're interested in not only adding reversible performance mods (a tune, intake & DPs), but also upgrading your supporting mods (CP + DVs/BOV) to make sure the car will keep up with the higher performance settings.

[BQTuning]

Originally Posted by texxy

......don't think I will go any crazy AFE setup since from reviews intake does not help this car much......

If you are referring to the aFe CAI you have been mislead. Being that you are leasing then yes I would say your move to get a DCI is a wise one.
However, for clarification for our readers the following are the results of the stock intake w/K&N drop in filter (in lower temps) vs the aFe Stage 2 Elite CAI (in higher temps)

[Beemw335]

Just get the jb4 for now, no you fo NOT need a charge pipe, thats on the n55.
As for exhaust, try out the canflap feature on the jb4, it might make you happy for now.

[BEAR-AvHistory]

Its all about what you want to get out of the car & how fast you want to go. With the JB4 current firmware you don't need much of anything but good 93 octane gas & the custom IS Map6 will generate north of 365whp (dynoed 365whp on the old maps) on a Dynojet & can be removed in 20 minutes for dealer service & end of lease turn in.

State inspection can be passed by leaving the JB4 installed & switching to Map 0.

BTW downpipes are very dealer unfriendly, will throw error codes & are not that easy to swap in & out, don't let anyone tell you otherwise. There are IS cars running very low 12's on full factory exhaust systems. IIRC BuraQ ran 12 flat on the factory IS exhaust.

[benzy89]

Originally Posted by Beemw335

Just get the jb4 for now, no you fo NOT need a charge pipe, thats on the n55.

What's are you saying?!

[Beemw335]

Originally Posted by benzy89

What's are you saying?!

The charge pipe on the n55 breaks very easily.

[benzy89]

Originally Posted by Beemw335

The charge pipe on the n55 breaks very easily.

The charge pipe breaks on the N54 + N55 at raised boost. I upgraded to an ER long CP before I started running Stg 2, but I have a friend that broke his CP right off the throttle body running 14 psi. It's been said 1020535 times, it's luck of the draw with the OEM DVs + CP. Some people's hold up when they're FBO while other people's break after just adding a tune

[N55]

Originally Posted by benzy89

Downpipes will have a substantial impact on your exhaust. Because you have a 335is, you already have the BMW Performance exhaust installed on your car, so going to catless DPs will not only give you a quality exhaust note, but will also give substantial performance gains. There are several DP brands that ar:

FWIW... From all my research the 335iIS does not have the Performance Exhaust. It is simply the stock exhaust with less material in the muffler. (Correct me if i'm wrong)

Also, my friend has a N54 E92 with the Performance Exhaust and his has a higher note than my 335IS

[benzy89]

Originally Posted by N55

FWIW... From all my research the 335iIS does not have the Performance Exhaust. It is simply the stock exhaust with less material in the muffler. (Correct me if i'm wrong)

Also, my friend has a N54 E92 with the Performance Exhaust and his has a higher note than my 335IS

It's like a hybrid of the regular exhaust & the PE. Basically falls right in between

[N55]

Originally Posted by benzy89

It's like a hybrid of the regular exhaust & the PE. Basically falls right in between

Correct

[RoundelM3]

Originally Posted by benzy89

It's like a hybrid of the regular exhaust & the PE. Basically falls right in between

Correct...and the 335is exhaust is notably less expensive than the PE as well.

Somewhere in there, you may want to give some thought to a larger oil cooler after you get some of the other mods that may raise oil temps due to the additional power you'll be making. ER makes a "Sport" model that replaces the stock cooler with one 3x larger. I recommend it highly.

Personally, I'd hold off on the DPs, because unless you want to have to remove them every time you take your new ride in for service, your dealer will frown heavily on them and may even request you to remove them before they do any work on your car. I'm almost out of CPO warranty on my car, so I'm considering getting the AR units with the hi-flo cats. I've started using an indy shop for my maintenance now and don't have to worry so much about the dealer.

[benzy89]

My dealer doesn't care that I'm FBO, but then again there's a guy with an M3 + ESS S/C and they don't bother him either

It's very subjective & completely depends on your Dealer, their Service Dept & the Warranty Administrator on how they approach a modified car.

[idrift4wd]

IMO, id jsut go with a tune and intake.

its a brand new car, and downpipes will usually get your car flagged for mods.

[BQTuning]

The 335iS stock is exhaust is not the BMW PE. Here is a picture of the stock part number:



You can see more pics here http://www.e90post.com/forums/showpo...38&postcount=1

The 335iS exhaust is more free flow and more agressive than the standard 335i stock exhaust. It is an in between or level down from the BMW PE

[FAM3]

Still out and about figuring out mods. Thanks again guys

[benzy89]

COBB AP FTW!!! Just get it, flash your DME & GOOOOOOOOO

Or if E85 is available near you, I'd look into the plug-in tunes since they support E85 fuel blends

[sickem]

Originally Posted by benzy89

My dealer doesn't care that I'm FBO, but then again there's a guy with an M3 + ESS S/C and they don't bother him either

JMK?

Yeah I've been to a few dealers with my catless DPs without an issue. (One time it was warranty work to replace one of the VANOS solenoids...the others just maintenance...)