Not sure what to make of this...
 

My 01 Monte SS was throwing a code for the MAF and a fuel vapor vent system issue. I have known about the fuel vapor vent issue. It is hard to put gas in the car at the gas station. The pump will keep shutting off when the car is not full. I have a new filler neck for it and plan on replacing the vent solenoid soon.

Anyway, I don't think the fuel vent issue has anything to do with what I am looking for advice on.

The car was "stumbling" under acceleration, so I ordered a new MAF sensor from Rock Auto and installed it yesterday. I also replaced the PCV valve just in case. I figured, for $3, why not.

The car was running like a dream since I replaced those parts. That is, until this morning. I was running errands and after one of my stops, the car wouldn't stay running unless I had my foot on the gas. It was not throwing any codes, but wouldn't stay running. I got it home and unplugged the new MAF. problem solved. I plugged the new MAF back in and it is running fine again. What the heck is going on?? Anyone have any ideas? I don't want to get stranded somewhere.