High AFR/ CEL

[JayM6]

Hey guys, have a 2015 CP M6. Car has 20,000 miles, and runs and performs great but recently had a CEL come on. I scanned it and go a p0175 code: system too rich bank 2. I cleared the code and it hasn't came on since but I haven't driven it much. Car is stock besides Turner exhaust and is running a BMS intake which has been running great for past month, so I'm not sure if this is related. I cleaned the MAFs. Obviously hoping to keep the intake for the sound and looks, hoping it's not the culprit. Does this seem like something I should be concerned about if the CEL doesnt come back on? Any insight guys? Possible o2 sensor?

[ByronUT_M6]

I'd suggest to first reinstall the stock intake and see if your AFR drops, if it does then obviously that's your problem. Could also be a faulty O2 plug/sensor that happened on my '13 m6. Either way I'd try and get it fixed asap as an afr in the 18's in extremely lean and could cause serious damage.

[JayM6]

Originally Posted by ByronUT_M6

I'd suggest to first reinstall the stock intake and see if your AFR drops, if it does then obviously that's your problem. Could also be a faulty O2 plug/sensor that happened on my '13 m6. Either way I'd try and get it fixed asap as an afr in the 18's in extremely lean and could cause serious damage.

I cleaned MAF's, reinstalled BMS intake, and disconnected battery for about 30 mins to restart ECU and AFR is showing in normal ranges again! Looks like maybe could've been a dirty MAF, along with a loose hose causing different readings

[JayM6]

Drove the car a bit more and same code
Came back on.. might install stock intake and go from there

[JayM6]

I put stock intakes back on, cleared the light but it's back on again..still showing both banks are showing rich. My long term fuel trims are both hovering around -15, but short term are around 0.8. Any ideas what can be causing this??

[BMWDriverX]

Originally Posted by JayM6

I put stock intakes back on, cleared the light but it's back on again..still showing both banks are showing rich. My long term fuel trims are both hovering around -15, but short term are around 0.8. Any ideas what can be causing this?? Oxygen sensors are also showing negative voltage, don't know if that's normal?

If your car is back to stock and this is still happening I would take it in, it's still under warranty isn't it? Could be a damaged MAF sensor or a million other things but it needs a diagnostic to find out which direction to go as far as repair.