1999 Pontiac Bonneville 3.8 engine 166,000 miles. it will start then die in about 4-10 secs ocaasionally will run for a few minutes then die. Fuel pressure is normal and flow is good. No engine codes of any sort. If you unplug the MAF it will run (idle is a little rough in this mode and it will then post a maf error code). Should I replace the MAF sensor? When it starts and runs for a few secs when it starts to die out there is a loud sucking sound form the air cleaner area I beleive the IAC is trying to bring the idle up. Any other ideas?

Watch the security light. A VATS issue will prime the fuel pump...and allow the car to start..then run on that fuel only. This sounds very possible..or a serious vacuum leak.

It never loses fuel pressure and the pump continues to run for a couple of seconds after it dies the pressure gauges then holds over 50 lbs pressure forever.

I had a similar problem with my son'* '99 Grand Prix. Had good spark, good fuel pressure, no vacuum leaks, etc. A new MAF took care of the problem. It is not an inexpensive part, so be sure to rule other things out first.

Well time will tell I got one from a salvage and put it on. Right now it starts right up and runs great. But it did that this morning before I went to work and it started fine this evening when I got home. Changed it after that. We will see. And yes that is pricey part $140 is the cheapest for a new one $40.00 for a salvaged one. It looked good so I think it is worth a try.