P0171 Error Code

[DKZTT]

Maybe this is common knowledge but I didn't know.

Well I've been getting P0171 error code and the CEL (engine symbol) would pop-up on the dash instruments panel.

For the 35I or 35IS, there is no MAF sensor. Our cars do have a MAP sensor instead. I should have figured this out when I installed the AFE intake and didn't have to unplug and re-install any MAF sensor to the new AFE intake.

So when the P0171 error pop-up, I researched and many of the postings or fixes were for the 3 series and I thought it would be the same for our cars. So I tried to find the damn MAF sensor along the intake track and never found one. I've looked through all the diagrams trying to find it but alas never found it. One call to BMW dealership talking to a tech and he informed me there is no MAF sensor, instead there is a MAP sensor.

Since replacing the MAP sensor, the error code has gone away...hopefully for good.

[rking117]

you may still have to clear the code from the vehicles memory. Just because you don't have a light doesn't mean it isn't still there. Clearing it now will allow you to diagnose the next problem without having to guess whether or not the code is new or old.

[nicknaz]

fingers crossed. other things to check are whether the aftermarket intake is installed tightly with no leaks, and that the front O2 sensor is ok

[DKZTT]

What's confusing was that a MAF sensor part number could be found for the Z4 35i on getbmwparts website even though it doesn't have one. After talking to tech, I checked RealOEM and confirmed it doesn't have a MAF sensor.

So far so good. Before the replacement of the MAP, I would get it so often it just became routine to clear and reset.