Wife came home from work yesterday and as she was pulling into the drive way she said the Monte Carlo stalled. She started it back up said that it stumbled a couple times and continued on into the driveway fine. I plugged in my scanner and it had a P0172 Bank 1 Rich code. I reved the car up once and it stalled. I then started the car back up and everything was normal I cleared the code and let it run for a little while longer, everything sounds normal, reved it a few more times and didn't notice any rich smell or anything.

A week ago it did almost the same thing only it had a code P0102 MAF input low, so I replaced the air filter (Dry element) and I replaced the MAF. It has ran fine since until last night.

Now that I have read a bunch of posts stating that the MAF is a common causer of this problem, is it possible that I got a defective one?

Any help is appreciated.

It is possible for the MAF to get "lazy" and still function normal to the PCM. And I'm not sure if the MAF could have anything to do with the P0172.

What kind of scanner do you have?

It'* an autoXray. Won't do much more than read engine codes.

Almost every post I read in a quick google search says that a MAF could cause this. Which to me makes sense, but I could be wrong.

Do you still have the old MAF sensor?

Had to turn it in for Core Charge........

Figures, gotta love those core charges...

Anyhoo, try disconnecting the MAF sensor and drive it around and see what happens.

??Was it an new AC Delco MAF sensor that you installed?

More info.

Looked at it last night when I got home from work. KOEO it has 48PSI fuel pressure and holds steady, running it maintains a steady 45PSI.

Since it said bank one I checked for vacuum leaks on the the front side of the motor and sprayed WD40 around the intake while it was running to check for a vacuum leak. I found nothing.

I shut the car off to take off the fuel pressure gauge so I could take it for a spin to see how it is running since I have not even drove the car in over a month, I did not even take it for a spin after putting on the new MAF sensor I just figured she would tell me if there was a problem still. When I started the car after removing the gauge, it started then stalled right out. It did that three or four times before it would stay running. I took off and drove it about three or four miles to let it warm up. After it did I gave it a little hard acceleration and around 3000RPMS it stumbled but kept running. I turned around and went to head home, stopped at a light and went to take off through the light I made it half way through the light and it stalled. I pulled off the side of the road put it in nuetral and it started right back up and I continued on home. Made it a couple more miles and tried the hard acceleration again and it did the same thing but when I let off the gas and started to slow down it stalled. Put it in nuetral and it started up and stalled out, then started again and I drove it the last quarter mile home.

Durring the whole drive last night the check engine light never came on.........

Talking with one of my friends he said he thinks its a bad cat, to me it seems to be fuel related, I would think if it was a cat I would be getting emissions codes.....

Also no it was not a ACDelco sensor, my only option that sunday morning was a Cardone from Advance Auto........

Can you make the same test drive with the MAF sensor connector disconnected?

Or at least around the block to see if you can duplicate the stalling issue?

also try putting the gauge so you can see it with the hood closed and watch it while you drive if it stalls and the fuel pressure doesnt go down first you know its not fuel related