Possible vacuum leak?

[mcvaughan]

For the past couple weeks I've been having RPM surging at idle; it even stalled on me once while car was running in the driveway. Took the car to my race shop and plugged into the computer and it showed a P00BD fault, having to do with possibly a MAF sensor issue or loose piping. We cleared the code, and it hasn't returned, however the car still idles rough.

FWIW, I have AMS catless downpipes, no tune YET.

Any thoughts???

[Used2be]

Originally Posted by mcvaughan

FWIW, I have AMS catless downpipes, no tune YET.

Any thoughts???

Your car is asking you for the tune! I'd think the real benefit of the catless DP is only realized when you're able to adjust fueling properly with a tune. I don't know the adaptability of the stock ECU, but it must be on the limit with the other reports of driving difficulties when hard on the throttle for cars with catless DP.

[mcvaughan]

Originally Posted by Used2be

Your car is asking you for the tune! I'd think the real benefit of the catless DP is only realized when you're able to adjust fueling properly with a tune. I don't know the adaptability of the stock ECU, but it must be on the limit with the other reports of driving difficulties when hard on the throttle for cars with catless DP.

Could be... Just find my situation different than others. Who knows, it's these crazy COMPUTERS!!!

[boots]

I never had that problem Matt. Give Alex a call at abr

[EuroKar]

Originally Posted by mcvaughan

For the past couple weeks I've been having RPM surging at idle; it even stalled on me once while car was running in the driveway. Took the car to my race shop and plugged into the computer and it showed a P00BD fault, having to do with possibly a MAF sensor issue or loose piping. We cleared the code, and it hasn't returned, however the car still idles rough.

FWIW, I have AMS catless downpipes, no tune YET.

Any thoughts???

Did the issue arise after the down pipe install ?
You can run catless down pipes on these engines with stock software and it will run fine. I don't agree with doing so as I believe that this mod needs a complete ECU reflash to operate and its best..but that's well argued in many many posts.
Anyways... check the operating values of the air flow sensor. There are some checks that need to be done with a good diagnostic program.
Something is going on for the fluctuation of the idle.

[mcvaughan]

Originally Posted by EuroKar

Did the issue arise after the down pipe install ?
You can run catless down pipes on these engines with stock software and it will run fine. I don't agree with doing so as I believe that this mod needs a complete ECU reflash to operate and its best..but that's well argued in many many posts.
Anyways... check the operating values of the air flow sensor. There are some checks that need to be done with a good diagnostic program.
Something is going on for the fluctuation of the idle.

Yes, it started happening after 1000-1500 miles were on the car. Maybe it did not adapt properly to the downpipes? The MAF sensors were checked and seemed to be operating properly. The car will be tuned on the 12th so I guess we'll see how it goes after that.

Thx

[EuroKar]

Tune ? As in performance tune ?
Don't do that. You will have the same issue
You should take it to a reputable BMW shop and have them figure out what issue you have going on. Then add the performance software after

[mcvaughan]

[QUOTE=EuroKar]

Originally Posted by mcvaughan

Yes, it started happening after 1000-1500 miles were on the car. Maybe it did not adapt properly to the downpipes? The MAF sensors were checked and seemed to be operating properly. The car will be tuned on the 12th so I guess we'll see how it goes after that.

Thx[/QUOTE

Tune ? As in performance tune ?
Don't do that. You will have the same issue
You should take it to a reputable BMW shop and have them figure out what issue you have going on. Then add the performance software after

Eurocharged will be diagnosing.

[mcvaughan]

Well, car is fixed. A number of issues were seen. Downpipes were originally installed without a proper seal. New air filters, MAF, plugs and coils were all done. Oil changed as well. Also had a couple instances of DTMAL. Software was upgraded. Car is running smooth as butter now...

If anyone in the Houston area needs a good shop for diagnosis check out MPower on Fondren.

[Used2be]

Originally Posted by mcvaughan

A number of issues were seen. Downpipes were originally installed without a proper seal. New air filters, MAF, plugs and coils were all done. Car is running smooth as butter now...

Good news! Was the neglected seal at the bottom of the DP or up top? Boots mentioned coils in his tune up also, is there something different about BMW coils? I had individual coils mounted on top of the plugs in my Lexus. Had the car for 16 years and never touched the plugs or the coils! Much less horsepower of course, but the coil just produces a spark and if it's suitable for the engine, what wears out? Maybe I should do a search and learn something about the new coils.

[mcvaughan]

Originally Posted by Used2be

Good news! Was the neglected seal at the bottom of the DP or up top? Boots mentioned coils in his tune up also, is there something different about BMW coils? I had individual coils mounted on top of the plugs in my Lexus. Had the car for 16 years and never touched the plugs or the coils! Much less horsepower of course, but the coil just produces a spark and if it's suitable for the engine, what wears out? Maybe I should do a search and learn something about the new coils.

The leak was at the bottom, fortunately. Would've been a pain to get to again if it was up top. Not sure about the coils being any different; just know they aren't cheap! I think I need stock in Bosch! :-D

And FWIW, make sure you get oil changes every 5K miles. My oil was BLACK as night.

FYI, I have 48K miles on my car.