[Kennybruv]

Hello y'all I have been losing my mind trying to figure out what is causing my n55 to run rich, I did do a catless dp with new o2s. I did just buy a new post cat o2 since the one I bought previously was a cheap universal that I spliced. Car has a rough idle that does not fluctuate on the tach but is easy to feel or hear. I also was trying to diagnose the car today when my limp mode activated and rail pressure dropped to 90PSI, threw 2C01 code. I did check plugs aswell and noticed they are sooted up. Can a Failing HPFP cause all this ? Or is my 02 a good suspect.

Note: Small exhaust leak on mid pipe to downpipe connection. Didn't think this would affect readings though.

https://datazap.me/u/tyoken/log-1716...og=0&data=4-19 A pull from same day

[bimmerfan1972]

Sounds like a leak in the air intake system. I had the same thing when I added a cheap aftermarket cold air intake. It never fit well with the rest of the system and caused all of the symptoms you described. Turned out to be that there was a 1/4" gap that I couldn't easily see because it was on the underside of where the ducting for the old system and new fit together. I ended up replacing it with a more expensive but much better fitting and higher quality intake. Fixed the problem and added bonus, my turbo sounds amazing. I used HPS Cold Air Intake Kit 2011-2013 BMW 335i. Don't know if this is your problem but it's worth taking a look. Although I believe my code was lean, not rich.

[wheela]

That log you attached looks really good. Your LTFT% and STFT% are both under 5% for the whole pull. I didn't see that you included lamda target, but your lamda actuals look right in line to me for the 1.60 stage 2+ 93oct map. And your rail pressure is solid in that log.

Other than going into limp mode that time at WOT is your issue more the lumpy idle vs. WOT? Do you have any logs at idle? It would be good to see what your AFR and fuel trims are doing at idle.

[Kennybruv]

Originally Posted by wheela

That log you attached looks really good. Your LTFT% and STFT% are both under 5% for the whole pull. I didn't see that you included lamda target, but your lamda actuals look right in line to me for the 1.60 stage 2+ 93oct map. And your rail pressure is solid in that log.

Other than going into limp mode that time at WOT is your issue more the lumpy idle vs. WOT? Do you have any logs at idle? It would be good to see what your AFR and fuel trims are doing at idle.

I have a couple logs at idle I'll try to find them rq and send them over, I'm also in the process of doing my vc and intercooler upgrade as we speak, I noticed a bit of oil in the vacuum lines and intake so maybe pcv went bad ?

[Kennybruv]

Originally Posted by bimmerfan1972

Sounds like a leak in the air intake system. I had the same thing when I added a cheap aftermarket cold air intake. It never fit well with the rest of the system and caused all of the symptoms you described. Turned out to be that there was a 1/4" gap that I couldn't easily see because it was on the underside of where the ducting for the old system and new fit together. I ended up replacing it with a more expensive but much better fitting and higher quality intake. Fixed the problem and added bonus, my turbo sounds amazing. I used HPS Cold Air Intake Kit 2011-2013 BMW 335i. Don't know if this is your problem but it's worth taking a look. Although I believe my code was lean, not rich.

I have the BMS aftermarket intake but I did install my OEM box and the idle didn't seem to change, it's weird because I'm getting 0 codes besides after I reset my lambda adaptations it threw the Low fuel pressure code and car went into limp mode.

[Kennybruv]

Should be idle logs

https://datazap.me/u/tyoken/log-1716...23-244-128-324

Log where my rail pressure crashed after adaptation resets

https://datazap.me/u/tyoken/log-1716...1&mark=264-359