[Wilson335i]

I unplugged one of my oxygen sensors bec I thought it was bad and it didn't do anything to how my car was running... and didn't trigger a engine light either. It was bank 2 sensor 1 with the grey wire and I've been getting really really bad gas mileage I just put fresh tune up plugs and coils but that only helped a little bit occasionally I get misfire on cyl 4-6 (bank 2) does anyone know what this could mean? I have rough idle and some morning have very rough starts lots of smoke.. gas mileage horrible until clear of code no excessive oil leaks I do have crack in valve cover any help appreciated I really would like to enjoy the car without worrying every second or looking at mpg gauge 😅

[BashShah]

crack in in the VC is your leak and causing of all your issues.
air getting into the car from VCG.
this causing you to run lean and poor gas mileage.

Your O2 sensor is not a O2 sensor but a AFR sensor.
read up on it.

After VCG replacement, do a Full Adaptation reset.

[Wilson335i]

Originally Posted by BashShah

crack in in the VC is your leak and causing of all your issues.
air getting into the car from VCG.
this causing you to run lean and poor gas mileage.

Your O2 sensor is not a O2 sensor but a AFR sensor.
read up on it.

After VCG replacement, do a Full Adaptation reset.

Ok what is a FULL ADAPT reset? I'm going to change that valve cover I have it already with gaskets and bolts however I do believe your correct my "02" sensors seem like they're working as they should.