2002 Chevy Malibu Problem

I've been dropping money into my wife's car left and right the past 2 months. New tires, brakes, rotors, fuel pump, fuel filter, blown head gasket, radiator flush, and now it is hesitating and making a pulsing shake while driving. Head gasket and radiator flush was due to brown sediment in the coolant reservoir noticed during an oil change. Since that oil change, it has been all down hill from there with the fuel pump being next to go.

The pulsing occurs at all speeds (from idle to 65), and the car has actually stalled at stop signs. The check engine light finally came on, and the diagnosis was the O2 sensor. O2 sensor was replaced on Sunday, and within 5 miles of the garage, it started pulsing again. Took is back to the shop and they said they had no idea, to take it to a transmission specialist.

Transmission guy took it for a test drive and said it had nothing to do with the transmission and said to take it back to them to fix. While he was in the car, check engine light came on again with a list of errors. O2 sensor again, Mass Air Flow/ Vacuum sensor, spark plug timing...

Went back to the shop and they replaced the mass air flow on the top of the engine, and said it should be fixed as of Sunday evening. Driving the car again last night and the pulsing is back, as if it is not getting enough fuel, or is being choked by something, and there is no check engine light.

Is there anyone out there that might know where to start or what the problem might be, as the mechanic I am working with is just throwing parts at the problem and guessing, and the bills are really starting to rack up. Thanks in advance for any help or advice.

Check to make sure the transmission isn't too full of fluid. Very important on that particular car.

Sounds like the idle air control valve

Read the attached article I wrote about a problem like that one on a car like yours. The lady had spent 2000 bucks and we fixed her car for almost no money.

You may have a different problem than the one I outline, but somebody has to get serious and properly interpret what's going on. The Idle Air Control valve won't cause a surging while driving down the road.

Nobody would have believed the Malibu I wrote about was a transmission problem - not even the transmission mechanics, but the car is fixed.

Your situation is a heartbreaker, and you need a real mechanic.