[MineralF30]

Hey guys, Ive got a 2009 E92 with a Speedtech bottom mount kit. Full E85 with port injection.

Ive been having O2 issues whenever my car cold starts. When I start it, both AFR readings start off normal. After about 5-10 seconds Bank 1 AFR shoots up to 40+ and keeps climbing. It causes the car to sound like its only running on 3 cylinders and its irritating because I cant let the car sit and warm up.

Once i start driving, the only way i can get it to stop misfiring is if I let off the throttle and coast in gear to reset the sensors. Bank 1 AFR maxes out as usual (234.95) and my idle issues go away completely, and it never comes back for the remainder of the drive. Bank 2 however doesn't max out at all, it only gets up to about 170ish which is really odd to me also. I've tried resetting Lambda & Idle adaptions multiple times and that doesn't fix it either.

These are usually the codes I get while idling:
29E0: Mixture Control
2A2B: Mixture Control

These are random codes I'll get after driving every now and then:
2C7B: Oxygen sensor after cat converter: Signal
2C7C: Oxygen sensor after cat converter: Signal
2CA8: Oxygen sensor after cat Function
2AC8: Oxygen Sensor heater after catalytic converter Function

I have replaced all four O2 sensors about 2 months ago with brand new NTK sensors, so they have less than 2k miles. Me personally I'm leaning towards bad sensors again but I cant even narrow it down to which ones are bad. Anyone have advice on what it could be?

Cold start data log: https://datazap.me/u/zlewis819/o2-se...16-17-22-23-24

[Mustafa.e92]

bad sensors mine were shot out the box I'm gonna stick with Bosch and use the warranty when they fail

[MineralF30]

Originally Posted by Mustafa.e92

bad sensors mine were shot out the box I'm gonna stick with Bosch and use the warranty when they fail

I'm leaning towards bad sensors as well.. I figured NTK's would be better for single turbo but sticking with OEM is probably the way to go and get the warranty on fcp

[Mustafa.e92]

Originally Posted by MineralF30

I'm leaning towards bad sensors as well.. I figured NTK's would be better for single turbo but sticking with OEM is probably the way to go and get the warranty on fcp

That's exactly why I got the ntk for my single but I had issues with the car and just installed them to see if it was an 02 issue. They would always stick lean. changed them out after 3 days with my old sensors and the downpipe and turbo was covered in soot from the dme dumping so much fuel

[MineralF30]

Originally Posted by Mustafa.e92

That's exactly why I got the ntk for my single but I had issues with the car and just installed them to see if it was an 02 issue. They would always stick lean. changed them out after 3 days with my old sensors and the downpipe and turbo was covered in soot from the dme dumping so much fuel

Makes sense, thanks man I guess I'll go order some Bosch ones and get those trash sensors out the car