Originally posted by r0ckstarr When MAF sensors go out they usually throw a check engine light and the car runs like crap or get's bad gas mileage. Do you have any of these symptoms? Here's the backyard way of testing the MAF sensor. Most of the time it's a surefire way to tell if the MAF is bad.
Start the car and let it idle for a few minutes. Once it reaches normal operating temperature, tap on the sensor with the handle of a screwdriver. Just a few repetative taps will do. If the cars idle changes, or stumbles a bit while doing this, it is bad.
Also, check eBay for a used one. A new one for my truck is $260. I found a used one on eBay for $46.00.
Wait... Audi? Can you even find the MAF sensor under the hood with everything else packed in there?
Precisely.
Here is the history on this. About 3 years ago, that stupid check engine light all sudden came on, and obviously fearing imminent explosion I took it to my mechanic, whom I have been going for over 10 years. He checked out the car, reset the check engine light, and off I went (he did this for free). About a thousand miles later, it did the same thing. We repeated the drill again (he did this for free, again), and off I went (without being blown to bits and pieces). Then the time came to do the smog inspection. This was 2 years ago. It didn't pass then. So my mechanic reset it again (no charge, again), and I drove it around for about 30 miles, and took it back to smog inspection, and at that time the car passed, along with me I guess. Then the 2 years had passed, and this time around resetting the check engine light and driving around didn't do the trick.
So, my mechanic, who is a better diagnostician than me the physician, said that it was a air mass sensor. He got the part for $275, and charged me 200 to put it in. I need to drive around for about 100 miles and take it back.
The symptoms my car was having was exactly what you described. It had been driving like a complete shit. Although I didn't tap on this thing, I am sure my mechanic did. We trust this guy, he has been there for years and years, he has won numerous awards for his honesty (if you can believe that, a car mechanic for honesty).
So five hundreds of George Washington have left me already.