W204 ENGINE LIGHT CAME ON




Could not observe anything wrong with car's operation.
Dealer came out and reset computer, Cylinder 1 running rich. No fault found, message did not re-appeared on test drive. Never had this before.
Could it be feul ? Anybody had similar experience ?

Monitor for code storage with an OBDII scanner.




Symptoms I noticed since they replaced the L5 crank sensor at around 13-15 000KM.
Since new up to L5 replacement:
1-Starting from cold it would ref up a bit rev down to idle smoothly, exhaust sounded "closed & normal".
2-The engine was silky smooth, no changes in revs after warmup, rev counter solid.
3-The only problem was that it would not start 4x times out of 13 000Km, it cranks but no start, till key is removed=L5 solved that problem.The problem was also indicated on tester.
Since L5 replacement:
1-Starting from cold it revs up a bit, and here is the change, the exhaust sounds "open & blurpy" (lean ?)with blabs till it warms up and revs down to idle.
2-After warmup the engine would slightly change revs up-normal-down and so on, rev counter not solid.It is still doing it. It showed nothing with tester connected the other day.
3-The car went through all the services and still the same, nothing "corrected" or found.
Could this also a further indication of the MAF sensor or something related in that region ?
A stupid question:I remember driving in very windy conditions the day Engine light came on, car was pulled over the road etc, could a blob of forced wind be forced into the aircleaner or suction be a cause, just a wild thought?
Thanks
Last edited by Moto_Guzzi; Jan 9, 2012 at 02:45 AM.

These cars go onto high idle, open loop, mixture enriched from a cold start. If MAF is dirty or air cleaner seal is bad they will behave well with enriched mixture but as soon as they warm up & go closed loop with leaner mixture they hunt at idle.
They also need to check that your new CPS is OK.
These cars go onto high idle, open loop, mixture enriched from a cold start. If MAF is dirty or air cleaner seal is bad they will behave well with enriched mixture but as soon as they warm up & go closed loop with leaner mixture they hunt at idle.
They also need to check that your new CPS is OK.
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These cars go onto high idle, open loop, mixture enriched from a cold start. If MAF is dirty or air cleaner seal is bad they will behave well with enriched mixture but as soon as they warm up & go closed loop with leaner mixture they hunt at idle.
They also need to check that your new CPS is OK.




I hope this was the problem. I could have done this myself, but car underv MP.





I am however glad this problem is gone(Sometimes I walk to back of car after starting it from cold, just to hear), because I was sure about it, however minor.



