MAF Sensor location?

[Hearts88]

Hi, recently the "service engine soon" light has come on in my 99Lumina (3.8L).

I had it scanned where my brother in law works.(he's the detail guy)
3 codes came up...
p0102 - mass air flow sensor circuit signal low
p0440 - evap emissions system fault
p1665 - evap vent sol con trol ckt

The mechanic cleared the codes, then started the car to see if the engine light would come on again.

It did, and he re hooked it up and the MAF code came up again. He figured that the MAF is the initial problem because if it isn't working that it could have made the other codes come up.

My question is, is he right? Could the MAF sensor failing be the reason for the other 2 codes.

The other question is, the mechanic told my brother in law that I could try cleaning the MAF sensor with throttle body cleaner on a Q-tip. Is this a good idea????

My last question is where the heck is the MAF sensor?!?!? I am used to driving some really old cars and am not familiar with the MAF sensor. I have read about it and what it does... but no idea where it is on my car or what it would look like.

Thanks in advance for any help.
Hearts88

[maxwedge]

It is in the throttle body bolted to the side and the sensor wires project into the airstream, make sure you are gentle cleaning them and use CRC maf cleaner or electrical parts cleaner. This is not related to the evap code, unless you had a bad vacuum leak.

[tblake]

isnt an evaporative emmisions code usualyy cause be a loose gascap, and not a vacuum leak?

[maxwedge]

Originally Posted by tblake

isnt an evaporative emmisions code usualyy cause be a loose gascap, and not a vacuum leak?

You are right but the evap codes did not reappear, only the maf. Of course after the monitors reset they may well return.

[richtazz]

The two emissions codes could be related, but aren't related to the MAF code. I would recommend only spraying the MAF, not using the q-tips. The MAF uses a coiled filament (similar to a light bulb filament) to guage airflow into the engine. The air flow cools the filiment, and changes it's resistance. The PCM monitors input and output signals to determine the proper injector on-time to keep air/fuel mixtures proper. If any little pieces of q-tip get on the filaments, the MAF is ruined. A far as the two emission codes, check the wiring harness at the vent solenoid (mounted on the front of the engine near the upper plenum, between it and the front valve cover) as the P1665 usually indicates a bad signal to the PCM from the vent solenoid. The P0440 could be a loose gas cap or could have been caused by what ever caused the P1665. If they don't come back after dealing with the MAF sensor, then I wouldn't worry about it.