My autotap says I am throwing a p100 code. So, I check the wiring going to the MAF. 13.0 volts from the Battery, and 5.00V reference so that is good to go. My MAF is practically brand new, I bought a GMS MAF and I'd say it dosn't have any more that 3-5,000 miles on it. I took it out and cleaned it with alcohol and q-tips just to be sure and still I am getting p100 and a air fuel ratio of 14.2:1 What the hell could it be? Any ideas?
Thanks,
Tony

 

I've had this problem since I bought my 96 Z in November of 2001. It pisses me off and nobody that I've talked to knows exactly why. When the MAF code came up, I went out and bought a Granatelli. The SES light still persists, and that code still comes up. I don't get it!! I haven't had the money to take it to a dealership yet because of all of the money I'm putting into my POS. Since I bought it, I've put over 3 grand into this thing to get it running right and I still need to get the tranny checked for a grinding noise, and it vibrates really bad after 2000 rpm in 6th gear. My paint is bubbling and chipping because I hit a dog. just bought my second set of tires. Sorry, I'm venting. Hope you can figure this out. If I find anything I'll let you know. Sorry I can't help now.

 

well damn, huess that makes two of us... anyone have a solution for us????

 

How did you check "5.00V reference"?. I don't think there is one, unless the frequency signal rides on the reference voltage. There are three wires to the MAF... +12V in, ground, and variable frequency signal out to PCM. You need a frequency meter to check the output signal.

How do you know you are getting 14.2:1 A/F ratio? Did you put it on a wide-band? And is that in closed loop, or at WOT?

Do you have a log showing MAF gps values for different operating conditions?

Just trying to help, but the first two points are a little confusing.

Is the SES constant, or can you clear it and wait a while for it to come back? I have seen a few posts about MAF problems that eventually are tracked down to a faulty +12V wire. Seems like there is something in the harness that causes a continuity problem over time.

 

I HAVE THE ANSWER!

I had the same problem you all did and you know what the answer was...........

A FUSE! It's under the hood. It's called engine sensors. replace that fuse, I'll bet money yours is popped.

I tried all different things, testing the voltage like you said, etc.. even went as far as hot wiring the wire to a fuse under the dash... In the end it was all just the fuse.