Idle and Stalling Issue

[Evo23IG]

Hey guys, let me give the background first on my car, its 2011 BMW 135i with 60k miles. I bought the car a few months ago and it had some mods which are Injen Intake, Evolution Motorwerks Charge pipe, Burger Tuning Harness, Down pipe, Berk Mid Pipe, Stock Axle Back with muffler cut out.

The car did NOT have the stalling issue but it did hesitate when getting on WOT in the higher RPMs. I decided to bring it back stock. Took everything back to stock except the Berk Mid Pipe. Then I was starting the get the idle and stalling issues plus was getting the faulty codes P2177, P115D and P3237 once in awhile. I changed the MAF sensor which helped a bit and got rid of the P115D and P2177 code. But I was still getting a somewhat a rough idle and stalling issues once in awhile, also one time I had the stall and it threw the P3237 code. The P3237 - Control Module Monitoring Fuel Correction Error. Any suggestions would help greatly where to start looking for the problem

Also worth noting, the car was always serviced at BMW dealership up to 47K Miles with all the maintenance completed thru the BMW program. I have 13 service records the dealership.

[E46NAQ7]

I would take a look at the ignition coils, that was my issue. I had a similar problem like that where I would have the hesitation on WOT and it would occasionally stall at idle. I would maybe start sparks > coils > HPFP > Walnut Blast...hopefully not the fuel injectors.

[Evo23IG]

Originally Posted by naqvibmw

I would take a look at the ignition coils, that was my issue. I had a similar problem like that where I would have the hesitation on WOT and it would occasionally stall at idle. I would maybe start sparks > coils > HPFP > Walnut Blast...hopefully not the fuel injectors.

Well the hesitation has pretty much gone away since installing the stock parts back on. I am definately going to do the sparks plugs, I have a set in my garage.

[Evo23IG]

Took the car out of the garage today, right away got P2177 code then the car went into limp mode. Cleared the code and restarted the car everything was back to normal. Later on the drive I got the P115D code, then got again later on that night after the was sitting parked for a few hours. So I am guessing the MAF sensor is not an issue. Maybe it could be the O2 sensors?

[E46NAQ7]

I'm about 80% confident it is your ignition coils. I got that same code where it said the fuel system is too lean. It turned out to be the ignition coils. The mods accelerate the wear on them too, but definitely do those spark plugs that you have ASAP. Also check the bank to be sure your valve cover gasket isn't leaking.

[Evo23IG]

Originally Posted by naqvibmw

I'm about 80% confident it is your ignition coils. I got that same code where it said the fuel system is too lean. It turned out to be the ignition coils. The mods accelerate the wear on them too, but definitely do those spark plugs that you have ASAP. Also check the bank to be sure your valve cover gasket isn't leaking.

The valve cover gasket is good, that was checked already. I going to pull to try to pull the plugs tomorrow and check the coils. Anything specific I should be looking at the coils for?

This is what I came up for the P2127 code that could cause the problem.

The fault is recognized when
the mixture is too lean and
must be enriched by more
than 25-30%, depending on
load factor.
Potential problem source(s):
- Oxygen sensor before
catalytic converter defective
- Mass-airflow sensor
defective
- Defective injectors
- Intake-manifold pressure
sensor defective
- Intake-air temperature
sensor defective
- Camshaft position sensor
defective
- Defect in high-pressure fuel
system
- Defect in low-pressure fuel
system
- Intake system leaking
- Oil cap not sealing
- Exhaust System Leaking

P115D Code:
Potential problem source(s):
- Collateral fault caused by
other components in the
intake system, Valvetronic,
turbocharger
- Intake system leaking
- HFM defective

[E46NAQ7]

Unfortunately there's not really an easy way to check the coils unless you go and buy one and swap each one out one by one and see if it causes the problem to go away. I got the camshaft position sensor fault code, fuel system too lean, etc. They all went away after I changed the coil.

Perhaps someone else might have some more suggestions?

[Evo23IG]

Originally Posted by naqvibmw

Unfortunately there's not really an easy way to check the coils unless you go and buy one and swap each one out one by one and see if it causes the problem to go away. I got the camshaft position sensor fault code, fuel system too lean, etc. They all went away after I changed the coil.

Perhaps someone else might have some more suggestions?

At that point just change them all. I have question, one the stock intake the pipe that goes from the intake box down to lower pipe of the intercooler, is there suppose to be gasket between or is just one bolt that holds down?

[E46NAQ7]

Originally Posted by Evo23IG

At that point just change them all. I have question, one the stock intake the pipe that goes from the intake box down to lower pipe of the intercooler, is there suppose to be gasket between or is just one bolt that holds down?

No, it's just the hose clamp and its bolt.

[Evo23IG]

Originally Posted by naqvibmw

No, it's just the hose clamp and its bolt.

Hose clamp? Are you sure the pipe is plastic on the left hand side.

[E46NAQ7]

If you can point it out in a picture maybe it'll help me lol, we may be talking about a different area.

[Evo23IG]

Connection between 1 & 14

[Evo23IG]

Just want to update the thread a little bit. I fixed a couple things so far, one I found that I was missing the rubber gourmet that goes between pipe 1 and 4 which took off my friends car for now. This gourmet seals the connection between the two pipes. Also my oil cap was leaking. Hopefully this takes care of the P115D code but I am not sure if I fully fixed the P2127 code yet.

Also questions when removing the Burger Tuning N55 Stage 1 harness, do you need to upload any file to the ecu or you just remove it from the car?

[Evo23IG]

After driving the car all day it seems like it this has cured the problems I have had. No issues with the idle and stalling, car has driven flawlessly.