HPFP Issue w/ Cobb AP?

[Onederer]

I own a 2008 135i that has 49k. So far the car has been awesome and hasn't given me a single problem.

However, I noticed that after installing my Cobb AP with a stage 1 93 oct aggressive tune and some spirited driving, my car seems to chug/lose power around 5k rpm's. This only occurs when im WOT and not during normal daily driving.

When this happened, the service engine soon light came on and has remained on since(from what I read, this happens when there's an issue with the HPFP, among other things). The car returns to normal when I shut the car down and restart it.

My initial guess is the the HPFP is shot, but when I remove the tune, this symptom does not happen at WOT. I don't think the HPFP flow is sufficient enough for the aggressive tune of the AP and as a result, I lose power.

I should be able to get the HPFP replaced, but my concern is that even if it's replaced, it still might not flow enough for the tune (just a guess).

Has anyone else had this issue with their tuned car? Is there anything else I can do to stop this from happening? I'm not here for a diagnosis I'm here because I know people have tuned their cars and may have had similar issues.

Any help would be greatly appreciated!!

Thanks in advance.

[135Pats]

its tough to say for certain whats causing your CEL, but i can say that with a healthy car (hpfp, injectors, plugs), stg1 aggressive should be perfectly reliable and safe with 93 octane. can you pull a decent data log? or is the power cut simply too abrupt. try stg1 sport and see if that causes the CEL.

[ErvGotti]

You'll need to read the codes until then it's anybody's guess. The AP has the ability to read the codes. You'll need to reinstall the tune get the CEL to come back on then read the code. My guess is spark plugs as that's what mine was.

[Onederer]

Well, allow me to be more clear. I didn't get a CEL, meaning, a light did not come on that reads "CEL" or "check engine."

It simply says, "Service engine soon."

Would these two terms be one in the same?

[ErvGotti]

Originally Posted by Onederer

Well, allow me to be more clear. I didn't get a CEL, meaning, a light did not come on that reads "CEL" or "check engine."

It simply says, "Service engine soon."

Would these two terms be one in the same?

SES or service engine soon is usually more severe than CEL or check engine light. CEL is usually emission related as where the SES is hardware related. Like I said you'll need to read the code until then it's anyone's guess. It could be the HPFP, Plugs, coil packs, vanos sensor, ECT.

[Onederer]

Originally Posted by ErvGotti

SES or service engine soon is usually more severe than CEL or check engine light. CEL is usually emission related as where the SES is hardware related. Like I said you'll need to read the code until then it's anyone's guess. It could be the HPFP, Plugs, coil packs, vanos sensor, ECT.

Thanks for clearing that up. I'll see if i can read some codes today and report back.

[RimasRS]

Could be boost leak also. But I agree just read the codes.