Quote:
Originally Posted by TestDrive
MAF needs "cleaned" much more often than it needs "replaced."
Changing MAF implies a reset of the ECU. Typically an ECU will take a few miles (eg 150 mile) to fully recalibrate itself. If you're FE drop is based on a scan-guage or similar reading, give the ECU a little time to tune itself in.
If you've already gone 150 miles or more and the FE is still down more than colder weather would account for, you might want to double check that the mechanic didn't introduce a spec of lint or crude on the new MAF when he installed it.
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Hey TestDrive, not sure that it needed to be cleaned only, may have been, but as I say it already was replaced (past tense)...
I'm fortunate in the A4 to not have to run a scan-guage or similar product the car has a nice built in system that tracks and displays Ave MPG, Ave Speed,
realtime MPG, engine run time in hours & mins., and approx miles left until the fuel runs out (which makes for a fun ecodriving game to squeeze out more miles then the factory computer thinks you will get)
Thanks to the EM Garage I can tell you that I've driven 1,899.9 miles since the service (
Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com) my lowest FE per fill up was on 9-27-08 first full tank after the service. I think the engine control unit (ECU) has had plenty of time to adjust...
I'm thinking secondary air injection system has an issue, this is very common on VWs and Audi's. the pump's plastic housing is just riveted together and they rust and break... also the combination valve has issues in these cars.
it really is a great car...