[Breadvans]

I have a n54 and I put in catless downpipes this weekend. I put a mhd stage 2 flash on it for 91 oct because the highest I can get is 92. I took it for a drive and after warming it up I floored it, and it left a giant cloud of smoke and wasn't boosting. I parked it, took it for a drive 5 mins later to see if it was just adapting, then next time I floored it was in limp mode. I got code p1200 and I cleaned my vanos solenoids, then flashed it back to stock. Then I drove it again and it was still in limp mode but I got code p1554 instead, anybody have a similar issue? I'm guessing it's most likely unrelated to the downpipes

[Bimmer_Bro]

Originally Posted by Breadvans

I have a n54 and I put in catless downpipes this weekend. I put a mhd stage 2 flash on it for 91 oct because the highest I can get is 92. I took it for a drive and after warming it up I floored it, and it left a giant cloud of smoke and wasn't boosting. I parked it, took it for a drive 5 mins later to see if it was just adapting, then next time I floored it was in limp mode. I got code p1200 and I cleaned my vanos solenoids, then flashed it back to stock. Then I drove it again and it was still in limp mode but I got code p1554 instead, anybody have a similar issue? I'm guessing it's most likely unrelated to the downpipes

Sounds like you may have accidentally swapped the 02 sensors during install. Make sure you didn't get them mixed up between the banks.

[Breadvans]

It said swapped O2 sensors, so I swapped the plugs and it didn't idle as rough, but that was before I got these codes. I had a lot of misfire codes and O2 sensor codes at idle before I swapped them back. It was just the plugs in the engine bay, i didn't swap them on the actual downpipes

[Breadvans]

Also want to add, I have a new hpfp and lpfp and have not done the intercooler yet. I'm on just stage 2 on mhd not the plus

[lookalikehuuh]

So step 1, get a proper scan tool.

A generic OBDII reader will only give you these generic "P" codes that don't give you nearly the information required to properly diagnose a BMW. You need to get a proper BMW specific scan tool OR and advanced OBDII (Like an Autel MK808 or better) so you can read the manufacturer specific codes. If you don't want to invest on a proper tool then look into downloading INPA/ISTA in this forum. There are also other great phone/adapter tools out there like ProTool from BimmerGeeks.

There is a huge number of diagnostic messages that your current scan tool just can't access and makes it nearly useless for troubleshooting.

Once you have the proper scanning tool that can actually read all of the codes that the car is seeing then you can begin a much better diagnosis of what is causing your limp mode.

[Breadvans]

Bump and update. I used protool and I got 2a98 and 3100. I cleaned my vanos solenoids and that didn't fix. It drives fine until you want to boost, then it'll throw you in limp mode until you restart the car. I heard a weird tick when revving the last time, like while I was downshifting I heard a solid 3 tick and it went away. Then I went to rev again and it happened again. Not really sure what this could be, and I don't wanna just throw parts at it if I don't have to

[Bimmer_Bro]

Originally Posted by Breadvans

Bump and update. I used protool and I got 2a98 and 3100. I cleaned my vanos solenoids and that didn't fix. It drives fine until you want to boost, then it'll throw you in limp mode until you restart the car. I heard a weird tick when revving the last time, like while I was downshifting I heard a solid 3 tick and it went away. Then I went to rev again and it happened again. Not really sure what this could be, and I don't wanna just throw parts at it if I don't have to

Any smoke coming out the exhaust on acelleration or Decel?

There are several issues that can throw those codes:
-Blown turbos
-Under the valve cover the bolts securing the Vanos actuators can come lose
-Bad crankshaft sensor
-Jumped timing
-cam bearing ledges

Edit* I see it did smoke when you floored it. Has it done that again?

[Breadvans]

Originally Posted by Bimmer_Bro

Any smoke coming out the exhaust on acelleration or Decel?

There are several issues that can throw those codes:
-Blown turbos
-Under the valve cover the bolts securing the Vanos actuators can come lose
-Bad crankshaft sensor
-Jumped timing
-cam bearing ledges

Edit* I see it did smoke when you floored it. Has it done that again?

No it has just done it the one time. I've been thinking blown turbos because it starts fine and drives fine under 40% throttle. It's a higher mileage car and this was the first upgrade I've done. I was also thinking I might've possibly blocked the wastegate with the v band. I'm not sure

[Breadvans]

Update, the bolt was blocking my wastegate but that wasn't the problem. I got it unblocked, cleared the codes, and immediately went into limp mode on startup. Exhaust vanos. I bought a couple solenoids that'll get here this week

[Breadvans]

Might be a goner. Pulled the little filters for the vanos, don't remember the proper name but the one on top looked like this. Installed new solenoids anyways but it still went into limp mode and has some pretty rough misfires at idle. Probably just going to sell it