Recently my 89 Firebird Formula with the 305 TPI will stall at a stop while driving. It accelerates normally when driving and doesn't seem to be losing any power. I started it up when I got home and it idles ok, however when driving, it will stall when I come to a stop or occasionally idle high briefly. I think it may be the IAC but I took it by a shop and they said the check engine code claims MAF. I replaced the MAF sensor a few months ago. I checked inside the MAF and none of the fibers were broken. It hasn't lost power or hesitates upon acceleration and drives fine on the highway. Could it really be the MAF sensor? I have to make a long trip next week and this bothers me that it suddenly has problems.

 

Well it wouldn't be the first time that Ive heard of a rebuilt MAF going bad shortly after getting it but before we jump to conclusions lets do a little trouble shooting. First off what codes did the pull?

 

I had an 85 IROC w TPI that used to fry MAF's. If you get a code 44, its a good chance its the MAF. My IROC would do the same thing as yours is doing. Unplug the MAF and see what the idle does. Should jump up to about 1000 at idle in park when unplugged. Everytime I used an aftermarket MAF, they would take a **** after a few thousand miles. If it's bad,get a Gm(Bosch) one. Worth the extra money.