[CoolHandLuke]

Hey Guys,

The background is I'm chasing a misfire issue since going FBO. I *THINK* it's injector since I replaced coils and plugs it's the next logical. Right?

Anyway I'm tying to understand what's the expected error codes for DP Fix + MHD. I have the following FBO setup of VRSF all around (except PE)

7" Intercooler + DCI intake + CP + Catless DP + DP Fix +PE

I live in MA so I believe that allows me 1 'NOT READY' monitor correct?

Looking at MHD I see four 'NOT AVAILABLE' categories. Would these preclude me from passing and thus I still need the DP fix - or - do these not count and I don't need the DP fix.

The following are marked not available. All else show 'COMPLETE'

- HEATED CATALYST
- SECONDARY AIR SYSTEM
- OXYGEN SENSOR
- EGR SYSTEM

29CC DME combustion misfires, several cylinders
29CF DME combustion misfires, cylinder 3
29D2 DME combustion misfires, cylinder 3
2C32 Lambda Control
2C6A Oxygen sensors after catalytic converter: mixed up
2C6B Oxygen sensors after catalytic converter: system check
2AAF DME fuel pump plausibility


Does anyone know exactly what codes are expected given the setup?

Also, I've seen a couple places that DP fix isn't recommended long term. I'm chasing a mystery misfire and wondering if this is related at all.

[zero2sixtyZ]

If you're running MHD and DP fix, start there. DP fix is not needed with MHD to pass inspection.

[RSL]

Originally Posted by zero2sixtyZ

If you're running MHD and DP fix, start there. DP fix is not needed with MHD to pass inspection.

EDIT: see zero2sixtyZ is in MA too, he'd probably know

Some places require cat to be ready even if they allow 1 MIL system not ready, so not blanketly true. You'll need to check your county's rules. If you're allowed 1 not ready and they don't specify cat system must be ready, you're good without the fix completely (as long as everything else is set).

Either way, yes, definitely only run DP fix if/when you need it to pass and then remove it, it will mess with adaptations. You're sure the O2 sensors are in the correct pipes too, right? Grey loom is rear DP, black is front DP.

[CoolHandLuke]

Thanks zerotosixty

Originally Posted by RSL

EDIT: see zero2sixtyZ is in MA too, he'd probably know

Some places require cat to be ready even if they allow 1 MIL system not ready, so not blanketly true. You'll need to check your county's rules. If you're allowed 1 not ready and they don't specify cat system must be ready, you're good without the fix completely (as long as everything else is set).

Either way, yes, definitely only run DP fix if/when you need it to pass and then remove it, it will mess with adaptations. You're sure the O2 sensors are in the correct pipes too, right? Grey loom is rear DP, black is front DP.

Mechanic did the work so I'm assuming O2 sensors were done right but I can ask.

You mention keeping them on briefly - It's about $200 for the DP install, assuming it cost just as much to get to the fix, are people swapping these out themselves or just eating the labor costs?

Would I have had this problem with JB4? Speaking with some people they swear by JB4+DP Fix = no problems but I can't believe this is unique to MHD...

[RSL]

Originally Posted by CoolHandLuke

Thanks zerotosixty


Mechanic did the work so I'm assuming O2 sensors were done right but I can ask.

You mention keeping them on briefly - It's about $200 for the DP install, assuming it cost just as much to get to the fix, are people swapping these out themselves or just eating the labor costs?

Would I have had this problem with JB4? Speaking with some people they swear by JB4+DP Fix = no problems but I can't believe this is unique to MHD...

Fix gets wired in to the DME. Where your mechanic physically did it, only they know. Most around here seem to attach them to the harness itself in the DME box (under the cowl). It is not the same as a DP install, it's simply connecting wires to other wires.

Yes, you would have the same problem with JB4, doesn't matter what you use. Essentially, codes for cat efficiency need to be disabled on catless DPs to keep the CEL off, which in turn, will keep the catalyst system from going ready. The only way to get the system ready is keep the cat codes enabled and use the DP fix to send a fake signal to the DME so it thinks they're working and won't trigger a light, BUT keeping it install indefinitely effects adaptations since the DME is making adjustments based on BS values. If it's an adjustable fix that's not set correctly, can trigger other issues and codes also. If it's adjustable and they just slapped it on where ever it was set, certainly a chance some of those errors you have right now are from the DP fix itself.

If you can pass emissions with 1 system not ready and cat is one allowed to not be ready, just pull the DP fix out.

[zero2sixtyZ]

Just pull the DP fix out. MA allows 1 non ready. Been on flash tunes since 2013, always pass inspection.