Hello everyone,

I recently purchased a C230K and I'm new to the family! My CEL came on reading P0170. I did all of my homework and "search" findings leading me to replace the MAF. I purchased and replace the old MAF insert with a new Bosch Insert.

Here's the problem. The car runs exactly the same as before and the CEL remains on. Starts and idles fine but completely misfires under exceleration.

I've read about the adaptive ODBII computer. Will I need to run it several miles from a cold start X 3 before it will clear the code or should the code be cleared out immediately now?

I recently had the car in for a Service2 and they told me the CEL was probably a bad MAF. They checked for vacuum leaks, etc.

I would appreciate your input... Thanks...[/align]

 

Is P0170 the only code?

P0170 is misfire and although the MAF is a good starting point it usually seen with a P0173.

The CEL does not go off immediately unless all Diagnostic Codes DTC's are cleared in memory. However if fault has been removed it may disappear after several cycles as you state even if the memory is not cleared manually.

Sounds like you have a different problem causing the misfire since youy say the problem continues.

Are you 100% SURE that the new MAF sensor is the CORRECT ONE and that it is GOOD? i.e. Where did it come from?

Since it looks as though you have a misfire....that is what the code is telling you....it could however be caused by 1001 things.

Air, Fuel, Spark, Electrics, Electronics.

Need to start from the beginning with vehicle history. mileage, when problem started, service history,better definition.... what do you mean by when you accelerate acceleration, how long have you had the car etc. if you want an answer that may correctly identify the problem.

Just to prove a point........... When were the plugs changed?

Stuart

 

Stuart,

Thanks for all of your input. The CEL finally went out after several days of driving and cold starts. The car runs great now after replacing the MAF.

Yes P0170 was the only code. I didn't have an ODBII reader or anything to reset the CEL. I just had to wait for the car to relearn everything.

I've only owned the car a few months, I'm not to sure about the history other than it was dealer certified.

Bottomline, if the codes point to MAF sensor try to change it yourself. $105 for the sensor and $2 for the torx 15 security bit and your in business. Saved over $400.00.

Todd

P.S.
I have changed the plugs