A few months ago, my 95 Impreza started idling rough/stalling and the CEL would flicker. So I pulled the code - 23 - Air Flow Sensor. I replaced the sensor and the car ran fine/code went away after ECU reset.

About two weeks ago, the CEL came on and stayed on. The car idled fine but seemed rev-limited to about 4000rpm. I pulled the code - 23 - Air Flow Sensor. So, I replaced it again on Friday, and the code went away, and the car ran fine.

For about 24 hours....

Tonight, the CEL came on, then about four miles later, the engine starts rough idling and quickly degrades to stalled out on the side of the road. In desperation, I unhooked the MAF. Car idles fine now, but back to the rev limited situation.

It seems really unlikely to me that I got two bad MAFs in a row. Anyone have any other ideas? The MAFs were both rebuilds... does the ECU have some issue with these or something? Is my ECU messed up? Bad wiring?

Thanks in advance for any advice/insight.

-adam

 

Are you running an oiled induction kit?
Have you checked the inlet pipe for any oil that might be damaging the MAF?

 

Nope... stock setup, and the airbox looks clean - not even a slight film of oil. I'm lost....

 

Sorry chap, no idea then.

 

Be odd for 2 to fail, and even more so on a MY95.

When you say they were rebuilds, I wasnt aware this was possible! That may be your problem because of the voltage is slightly out it will really affect the fuelling of the car. Could be rather dangerous in fact - unless whoever "rebuilt" them managed to give you a calibrated test for it you wont know.

I would check your wiring around the MAF plug and maybe find someone local that you could swap with as a trial. Unfortunately a new one is very pricey on your MY car. Maybe try a scrappie - if it was MY99/00 I wouldnt bother but it may be worth trying one that hasnt been messed with.

MB

 

Thanks for the advice, guys.

I'm going to try to convince the parts store to take back the rebuilt and credit me the money toward a new, Bosch MAF. It seems like if replacing the MAF the first two times cured the problem temporarily, then that rules out wiring/vacuum leaks, etc....