w210e55T

I replaced the MAF on my e55, and I didn’t have a rough idle before, but I do now. It was a new, OEM Bosch unit. I replaced pre-emptively given the age and mileage (98k kms). After installing I disconnected the battery for an hour as recommended.

The rough idle is almost always when in drive and stopped at stop lights or waiting in traffic. It’s intermittent but pretty regular.

Would the new MAF have triggered another issue or is it somehow not installed correctly? I’ve double checked twice and it seems to be fitted correctly?

Any ideas much appreciated.

cm60k

Bad MAF could cause rough idle or bad starting or intermittent acc. angle,,

prefer if you can diagnose the car, to make sure if anything else could causes the issues..

-;-ZAYED-;-

mbwillgrubs

Perhaps a vacuum leak if an o-ring was pinched or the MAF is inserted crooked. I would have problems pinching o-rings on a Jaguar I had.

6spd

Just wanted to add on to this. I had a drivability issue with my MAF. Low power, hesitation etc. I bought a brand new bosch installed and it still ran funny. After I disconnected the battery to reset the ecu. WOW completely different animal! So your car ecu holds on to a/f/ timing tuning based on the sensor inputs. So just reset when doing new sensors/electric parts.

Also I always reset the ecu when having drivability concerns for this reason.