hey guys my car has been running like crap... missing and barely idleing so i checked over everything was getting no check engine light or anything ...so as my last resort i disconnected my maf sensor all the sudden ther car idles great and runs like a champ...of course now that it is disconnected it showing a check engine light ...but if i have a bad maf sensor why was it not showing a check engine light with it hooked up?

 

Scan for codes. It's possible that you already had an error code stored in the ECM (even with the SES light off), and when you disconnected the MAF, it set an additional code, and triggered the SES light along with it....

 

so does that mean i have a bad maf ...just what to be sure before i spend that kind of money ?
its just weird that my car runs great with the maf disconnected

 

..just want you to know Ive spent a few hundred dollars
chasing this same problem around for a few weeks.

I cant stress enough that you check both MAF power
and burnoff circuits for correct operation before suspecting
a MAF sensor.

Vader has posted one of the best walkthroughs on how
to go about diagnosing a MAF problem.

Was your sensor descreened?

 

I wouldn't say that engine runs great without the MAF sensor, just that it's able to idle, and is a little more driveable than it's current state (this is because of the pre-determined VE tables when the ECM is triggered into Limp Mode). You'll need to scan for codes using the old paperclip method, this way you can at least get an idea of what's at fault here. It could be anything, including something very minor of a pulled wire terminal in one of the connectors. Don't be so quick to assume it's the MAF itself, as provided you didn't hit it with anything, chances are it's an entirely different sensor that works in conjunction with the MAF. We'll be shooting our arrows in the dark until you scan for codes though...

 

yes it is descreened ...and i will try the paper clip method and see what comes up

 

ok figured it out ..thanks guys its my burn off relay not gettng voltage to the maf ..... took off relay and jumped voltage to the blue wire and she ran great