Bad MAF?
Bad MAF? Just a quick question here. My car has had its MAF replaced recently with a used unit due to a check engine light (solved the problem for a few weeks). Then the car started bucking and hesitating again, but there is no check engine light on this time around (as opposed to last time). However, when I disconnect the MAF the car idles smooth, doesnt bog when leaving a redlight, and I obviously get the check engine light for the missing MAF. My question is this: is the MAF bad or does the car just run better because it is tripped into "open loop" mode due to the absence of the sensor, thus causing the computer to use pre-fabricated values for other sensors that could be bad? I have tried cleaning it after the car started running weird but got no results and the SES light never comes on. Please advise so I can get a new MAF for inspection purposes.
sounds like the maf is bad, unhooking it doesn't send the pcm into open loop, it sends it into closed loop speed density.It'll still run off the o2 sensors, but if the problem goes away with it unhooked i'd definatly suspect it. Try to find someone elses known good maf you can swap in rather that just shotguning a new one in with out absolute proof its the cause.
Alright, sounds good. I will see if I can verify that it is bad and get another unit. Thanks for the advice. I'm just tired of my car sounding like it has a cam in it when its slightly off idle and trying to stall at every throttle position below half.
The slightest bit of dirt can cause the MAF to malfunction. Pick up the appropriate cleaner and clean it.
BTW, if you are running an oiled air filter, that oil form the filter could be contaminating the elements on your MAF.
And SoCal, I think you have the open-loop/closed-loop terminology backwards.
BTW, if you are running an oiled air filter, that oil form the filter could be contaminating the elements on your MAF.
And SoCal, I think you have the open-loop/closed-loop terminology backwards.
Originally Posted by ShevrolayZ28
The slightest bit of dirt can cause the MAF to malfunction. Pick up the appropriate cleaner and clean it.
BTW, if you are running an oiled air filter, that oil form the filter could be contaminating the elements on your MAF.
And SoCal, I think you have the open-loop/closed-loop terminology backwards.
BTW, if you are running an oiled air filter, that oil form the filter could be contaminating the elements on your MAF.
And SoCal, I think you have the open-loop/closed-loop terminology backwards.
I just re-read it and it doesn't look backwards to me?closed loop=o2 sensor feedback, reguardless of maf or speed density
