I've got a 95 lumina with the 3100 v6, I am having problems with the car running, It starts up fine and even drives kinda good after it cools down but once you drive it for about 20-30 minutes you better hope your not in a hurry to get anywhere. It sputters so bad that 35MPH is about the fastest I can get it
I've changed the plugs wires and coil packs and this did not help. The plugs didn't look to bad really but I changed them anyhow. I've not been able to check fuel pressure yet but the Fuel pump is noisy as hell.
Does this sound like sound like a O2 sensor problem?