[Howun8]

My car is a F36 with around 36k mile on it. Recently I have upgraded to stage 2 remap from Active Autowerke with intercooler and hi-flow cat from Wagner and the Injen intake.

Right after that, the car now is having random stumble on idle, (ie. the rpm dip to 500 and jump back up to 700 and you can feel it just shake). And also, the car even stall when I stopped for traffic. The stall happened once or twice in a week, but its getting worse today, I had it stalled three times in a single day. It just stumbled and stalled.

I tried to pull codes from the car with ISTA today. It had registered one fault P0172 "Mixture control: fuel-air mixture too rich". I have checked there is no other error regarding the MAF sensor or O2 sensor stored. The plug was changed 5k miles ago.

Any hints how should I diagnose the problem? Its driving me nut because I didnt expect a stage 2 would cause me so much problem!.. It still pulls well when I give throttle, but the idle stumble and stall issue just made me no clue where to start.

[BettyFkinCrocker]

Originally Posted by Howun8

My car is a F36 with around 36k mile on it. Recently I have upgraded to stage 2 remap from Active Autowerke with intercooler and hi-flow cat from Wagner and the Injen intake.

Right after that, the car now is having random stumble on idle

Ditch the intake, problem solved. It does nothing but make noise and cause problems.

[Howun8]

Yeah, i was suspecting that too... I will swap back the oem to see if the problem goes away

[manghong]

Originally Posted by Howun8

Yeah, i was suspecting that too... I will swap back the oem to see if the problem goes away

I happen to have exact same issues, does removing the intake solve your problems? Thx

[Howun8]

Originally Posted by manghong

I happen to have exact same issues, does removing the intake solve your problems? Thx

Hey it turned out to be a leak between the intake butterfly valve and charge pipe after testing with smoke tester. Then I realised i didnt install the c clip properly when replacing my metal charge pipe. Now its all good. Shouldnt blame Injen lol

[manghong]

Originally Posted by Howun8

Hey it turned out to be a leak between the intake butterfly valve and charge pipe after testing with smoke tester. Then I realised i didnt install the c clip properly when replacing my metal charge pipe. Now its all good. Shouldnt blame Injen lol

Thanks man, I might have the same issue then. Cause I replaced the charge pipe, coils, spark plug and valve cover at the same time and dont know where to start. I might start looking the leak in the charge pipe first.