[bigtigga01]

Is this normal for my stft to max out so early in the rpm range. I'm trying to chase down this misfire issue and need help with the next step. So far I have replaced the precat O2 sensors, all fuel injectors, new coils and spark plugs, and walnut blasted was done last year. No codes either so I'm at a lost.

http://www.datazap.me/u/bigtigga01/1-25-14-logs?log=0
http://www.datazap.me/u/bigtigga01/1-25-14-logs?log=1
http://www.datazap.me/u/bigtigga01/1-25-14-logs?log=2

[AWTT335i]

That is not normal. I suggest resetting lambda adaptations using INPA.

[Mit_Boost]

You're maxed out from 3k-4.6k RPMs, so it's def not normal. I would recommend data logging fuel pressure for Low + High Pressure Pumps. You also might wanna take it easy because your AFR was 13+ the entire time trims were maxed out, including a 1k RPM range where it was 18/19 (that's motor failure bad).

[bigtigga01]

I will log those parameters next. When I replaced the precat O2 sensors the car ran fine for a day and went back to the same results with the STFT maxed out. Should I also replace the post cat O2 sensors? I didn't think they would effect the afr that much but I guess I could be wrong.

[Dmacc]

Originally Posted by bigtigga01

I will log those parameters next. When I replaced the precat O2 sensors the car ran fine for a day and went back to the same results with the STFT maxed out. Should I also replace the post cat O2 sensors? I didn't think they would effect the afr that much but I guess I could be wrong.

Possibly, over time oil can build up that has made it through your exhaust and could coat up your o2 causing iffy readings.

[Mit_Boost]

I don't think there's a problem with the o2 probes because after the your fuel trims recovery, you're maintaining a consistent high 11/low 12 AFR. It's definitely fueling related, so check your trims.


I had a similar issue, sadly ($$$$) new injectors was the only thing that fixed it.

[bigtigga01]

http://www.datazap.me/u/bigtigga01/12714-log

Did a log tonight with the parameters for e85, how do these look?

[bigtigga01]

Problem may be resolved. Seems at some point the computer parameters got out of whack and I needed to reset all adaptations using INPA as suggested. Once that was done I did some logs on different maps and the afr, stft, and ltft all seem to be normal.

http://www.datazap.me/u/bigtigga01/2...12&mark=17-112

http://www.datazap.me/u/bigtigga01/2...12-13-14-15-20

http://www.datazap.me/u/bigtigga01/2...20&zoom=15-109