Pontiac Repair: After starts car immediate dies, mass air flow, brain box

Question
I have a 1995 bonneville SE after I start up the car it immediately dies. Its only keep running when i leave my feet on the gas(when doing this its ofttimes sputter and backfire) but soon as I remove it it dies. I was told it might be the brain box but after remove the O2 sensor the check engine comes on so let me to believe that the brain box it working fine. Please help me. Also it has over 240,000 miles

Answer
hi Terry:

withe this many miles on the car the skies the limit as to what it could be. a few things to check are a leaking fule pressure regulator make, amke sure gas is not leaking into the vacuum line when it's running. Make sure the nthrottle plate and throttle bore are clean and not carboned up. The idle control valve may be gummed up as well Clean that. An O2 sensor is not going to make the car start and stall right away. You may want to try unplugging the mass air flow sesnor and see how it runs. The service engine lamp will come on and it may hesitate when it's running but overall if it runs better the sensor is bad. Good luck :)