how do test to see if a mass air flow sensor is good or bad? iam curious to see if mine is bad, because always at start up my car idle runs little rough then it goes away and if iam sitting at a stop light the idle isn't steady, idle seems to be stumbling, but it drives well with no problems, only when the car is at a stop the idle isn't to smooth, i have new coils, new ign mod, i cleaned the iac motor, new plugs, new pressure regulator, i check the injectors and they are good, iam thinking it might be the mass air flow sensor cause when i stop the idle doesn't stay smooth its little rough? also i get no codes, if a mass air flow sensor is bad would i get service light on? or can it go bad without the service light to come on?


1995 bonneville se model

A quick way would be to tap the top of it, with the butt end of a screw driver, while at idle. If the car sputters, the sensor is bad.

Otherwise your going to have to get the Chilton'* manual and get the DVOM out....

vette, sounds suspiciously like a dirty throttle body to me.

Remove the MAF sensor, and put it in a safe place (you can gently clean the filament of the sensor with rubbing alcohol and a qtip). Remove the TB from the car, remove the TPS and IAC. Now spray and scrub the TB for all you're worth with intake-safe cleaner. Pay particular attention to the IAC passage. Now clean the shaft, spring, and cap of the IAC. Put it all back together.

Even if this doesn't fix the problem (and it'* a 68.9% chance that it will), you probably need to do this anyway.