help me diagnose my problem

[Justin]

after I got my car back from the dealer the car has this problem of sputtering or breaking up rather on light throttle from 2800 to 4000ish rpms no matter the gear. I have tried doing a KAM clear and reloading the tunes. still it persists. It operates just fine under full throttle. My idea is its the plugs. I have 18k about on the car and ran e85 with a hard o2 fault for a week. I replaced the o2 sensor, it was very very black and wet or all things. I am also getting zero codes about anything going a miss detected by the ecu. its just so annoying.

my thought is to replace the plugs and coils with weapon x parts..selling point to the wife the car is due for the parts anyways and they cost less then oem parts (a lie I know)

Anyone have a easy test I can do to figure this out or anyone come across this studdering?

 

[cosm3os]

I've come across that in my BMW--it was an unplugged MAF.

 

[Justin]

well I got it sorted out.

the CEL came back on for P2626. contrary to multiple google searches bank 1 is not the drivers side it is the passenger side. so I put the known good sensor from the drivers side in the passenger side and left the raptor replacement sensor in the drivers. Did another KAM clear and idle relearn and it drives just like it used to prior to the fault.

I've come across that in my BMW--it was an unplugged MAF.

I thought that too was one of the first things I checked. if the above didnt fix it I was going to clean the maf sensor.