[sshah261]

Hey guys I was wondering if anybody can help me diagnose this issue. I bought my 335xi and put a PPK tune on there without any modifications and the car ran perfectly fine. And then I installed a BMS intake. Although, recently I installed an Active Autoworke FMIC and put a Cobb tune on it from the get go and the car began to bog when I am at idle or stopped at a light. In the morning the car turns on when it's a cold start but the rpm fluctuates a lot until the car starts warming up a little. So when I'm driving nothing is wrong with the car, although when at idle, cars RPM is bogging a bit and sometimes it comes to a point where it'll shut off on me when in idle. Also the Service Engine soon light has come on and has been throwing some codes. There has also been a couple times where the engine malfunction light came on but the car drove without any hesitation or any problems. So idk if it's the tune that's causing the problem or if there is a boost leak? Or is it something else? Anybody ever experience something like this before?

Help!

Thanks guys!

[flexbrah]

What codes did it throw? I heard that this could be an issue with some aftermarket intakes... I would try putting the OEM one back on and see if the issue goes away

[aaron_]

I had an oscillating idle rpm when I added my afe intake. Also could bog down and stall. Removed intake, no problem. Codes were all maf related. Removed intake. No problem!

Post up your codes. I recommend getting a custom mhd tune with maf scaling done. Will allow you to run your intake safely.

[weehe126]

Probably have a boost leak from the IC install. Also, COBB maps suck so could be that. The process I would take is flash back to stock and see if it bogs. If that doesn't fix it, put the intake back to stock. If that doesn't fix it start looking for the boost leak.

You really should ditch COBB and get MHD too.

[flexinator]

I had the jumping RPMs, sometimes stalling problem also. It happened when bone stock and when starting cold. It went away after tuning the car and I haven't had a problem since. By the way: it never threw codes and the dealer said it was "normal". No joke.

[sshah261]

I can see why you say the intake, although that was the first "mod" that I did when I bought the car and nothing went wrong at the time. It all started at the time after i put in the FMIC

here are the codes that came up:
- everytime i pull them something different tends to come up. The lastest one are the pair of pictures to the most right.

Thanks!

Originally Posted by flexbrah

What codes did it throw? I heard that this could be an issue with some aftermarket intakes... I would try putting the OEM one back on and see if the issue goes away

[sshah261]

Surprisingly my codes seem to be MAF related although when i first bought the car, that was the first thing i changed out and at the time it was running perfectly fine. My gut tells me it may be a boost leak. I am going to think about getting the MHD tune and just get rid of my cobb.

Originally Posted by aaron_

I had an oscillating idle rpm when I added my afe intake. Also could bog down and stall. Removed intake, no problem. Codes were all maf related. Removed intake. No problem!

Post up your codes. I recommend getting a custom mhd tune with maf scaling done. Will allow you to run your intake safely.

[sshah261]

i think its a boost leak as well. Hopefully its an easy find and fix if thats the case!

Originally Posted by weehe126

Probably have a boost leak from the IC install. Also, COBB maps suck so could be that. The process I would take is flash back to stock and see if it bogs. If that doesn't fix it, put the intake back to stock. If that doesn't fix it start looking for the boost leak.

You really should ditch COBB and get MHD too.

[weehe126]

Originally Posted by sshah261

It all started at the time after i put in the FMIC

Then it 100% is a boost leak. You are getting MAF codes because the engine is seeing more/less air than the MAP says it should.

[sshah261]

Thanks for all your input. I'm having the car checked out on Monday and I'll keep you guys updated!

Originally Posted by weehe126

Then it 100% is a boost leak. You are getting MAF codes because the engine is seeing more/less air than the MAP says it should.

[OneMoreAlex]

I had the same issue when I cleaned my BMS intake, didn't realize i sprayed a little too much oil on the filter and it gunked up the MAF sensor. I used CRC MAF spray to clean the MAF and reinstalled the factory airbox, codes never returned. I would recommend checking connections at the chargepipe & intercooler. If you don't see anything abnormal the easiest test would be to reinstall the factory airbox (assuming you still have it) and see if your problem remains.

[sshah261]

yes for sure! I will give that a try as well. Thanks!

Originally Posted by OneMoreAlex

I had the same issue when I cleaned my BMS intake, didn't realize i sprayed a little too much oil on the filter and it gunked up the MAF sensor. I used CRC MAF spray to clean the MAF and reinstalled the factory airbox, codes never returned. I would recommend checking connections at the chargepipe & intercooler. If you don't see anything abnormal the easiest test would be to reinstall the factory airbox (assuming you still have it) and see if your problem remains.

[OneMoreAlex]

Originally Posted by sshah261

yes for sure! I will give that a try as well. Thanks!

Hey, did you ever get this figured out?

[sshah261]

Originally Posted by OneMoreAlex

Hey, did you ever get this figured out?

Yeah just got it fixed 2 days back. So the problem happened to fix itself after i had the walnut blast done. They checked out for any boost leaks or anything with the intake, although the walnut blast fixed the problem. The car now runs like new!