Dirty LS maf sensor question.


Well-Known Member
Dec 31, 2005
I was reading in my text book about troubleshooting MAFs yesterday. It said if the film or wire is coated with oil or junk it will usually run lean at idle and rich everywhere else. Which is EXACTLY what my problem is. (I have 50% fuel added at idle, and MOST of my fuel pulled to the max everywhere else and it's still rich.) Though when I pulled my maf to look at it, I was suprised to see how small the little wires are. Could something that small still get coated with enough junk to cause this condition? Wouldn't it be easier to coat a hot film maf rather than a hot wire? How much oil could possibly leak from an aftermarket air filter to coat this little wire? In my past experience, (which may not sound like much, but it is actually a good amount) the goblins that cause a car to malfunction are NEVER, EVER, EVER the simple stuff, such as a "dirty air filter" or "dirty fuel filter" or "improperly gapped plugs" or "worn out plugs". It's NEVER that shit. That stuff RARELY fails. I've NEVER just changed out a set of plugs or a simple filter, and cured the entire car's woes. It only works that way on message boards.

In your guys' past experience, how often was a simply dirty maf the SINGLE HANDED cause of odd gremlins haunting your car's tune? I'm just curious. My brain's in an accelerated learning mode and I want to cram as much shit in it as possible. Thank you for your help.

One more question. I've also read that the hot wire mafs have a self cleaning cycle as well, where the wire gets heated to a thousand degrees for one second after the engine is shut down. Am I presuming our old ECUs aren't programmed to do this, since the hot wires weren't original to our cars? Is there any way to make this happen if our cars don't do this?
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