DontMixWithRice

How can you tell if a MAF is no longer good? (not the obvious answer: bending of wires and the lack of screen; which aren't the case here)

MyShibbyZ28

Have the car running, and the MAF plugged in. Open the hood and unplug the MAF. If it is still working and on the car will sound like it is going to die, then catch itself and keep running. If it is bad and not working, it will not do anything because it will already be in speed density mode.

LqMth

If its in SD mode shouldn't the check engine light be on?

TobyZ28

Couldnt a MAF go bad and give incorrect readings to the PCM without it being tottaly dead?

cammed_aro Z28

i have heard that with the car running, you can tap on the maf body with the handle to a screwdriver and if it is going bad, the car will sputter. dont know if it works or not, just a rumor i heard.

MyShibbyZ28

True...did not really think of that. If it is going bad though and still working you should see a drop in gas mileage.

MyShibbyZ28

How would that make the engine sputter? Maybe if it was really really really close to being dead and you kept knocking it in and out of speed density it would sound like it is sputtering, but only if it very close to dead.

LqMth

I think it has something to do with the connections on the "hot" wire inside. Theres a wire that is heated to a certain temp. and how much the incoming air cools the wire tells the computer the quantity/density of the air. They are pretty sensitive and if tapping on it alters the readings than something is wrong.

MyShibbyZ28

You would think if tapping it with a screw driver made it sputter, then when driving it would go mad. Corners, bumps, cracks, anything that causes vibration.

LqMth

If its going bad and something causes a hard enough vibration it will hesitate/ sputter. Just another reason you have to replace it. Tapping on a good one should not make it sputter indicating that its possibley not bad. Nothings ever definite with a car though. Its just a simple test that can help you diagnose.

DontMixWithRice

HAHA! Hooray! I figured out that my MAF works!

I got to work this morning, and I was a few minutes early, so I decided to open teh hood and take a look.

I pulled out the plug and death to smoochy!

Guest47904

It may mean it works but not necessarily the way it should.
If you want to test a MAF. Check the yellow wire for it's frequency response with a multimeter that displays frequency (Hz). Snap the throttle and see if the response is over 7kHz. If not, clean it. If that still doesn't give the correct response, replace it.