Mechanics

ROUGH IDLE ON A 330I

2006 BMW 330 • 91,500 miles

My SES light came on and my car started idling rough. It is giving me a P1415 code which says it is a secondary air system in bank one. My car does not have a secondary air system. I checked for leaks in the manifold, sprayed some carb cleaner around the intake manifold to see if there was a intake leak, no change. I disconnected each coil pack while it was running and the car ran worse, I changed the plugs and still get a rough idle when stopped at a light. My o2 sensors seem to be putting out around the same voltage, the fuel trim numbers are higher than normal,
-28% on the STFT and +26% on the LTFT. Could it still be the o2 sensor on bank 1 or is it a software problem.
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Paul323
August 29, 2011.




IT sounds like an o2 sensor. Check wiring to it for damage or corrosion. Let me know what you find.

Changed the O2 sensor on bank 1, still idling rough. Still popping obd code P1415. Next up I might change the intake manifold gasket, I did spray carb cleaner around it and there was no change. I am also thinking of buying one coil pack and go one cylinder at a time.
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Tiny
Paul323
Sep 10, 2011.
If there is no change in RPM when you check for vacuum leaks, don't waste your money and time with the gasket. It sounds like it is fine. As far as the coil, rather than buying one, switch the ones you have. That way you won't spend the extra money.

It does indeed have secondary air injection.

Dr. Hagerty
Oct 10, 2011.

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