I have a 2000 Grand Am with 205,000 miles (2.4, DOHC). It starts fine and runs fine, but after driving 10 to 15 minutes, when I stop at a light, the engine will die. It will re-start easily and will continue to run as long as I keep my foot on the gas a little. So far, I have changed the oil and plugs. I was going to try to change the fuel filter, but it is difficult to access without a lift. When I changed the oil, there was a "chocolate" haze in some areas, which I think indicates coolant in the oil, which could be from a blown head gasket. I am not sure what the oil usually looks like with a blown head gasket, so I might be mis-diagnosing here. Since I would like to avoid changing the head gasket, I bought some Bar's Leak head gasket fix, which I will try soon. I am requesting potential causes and fixes, and other diagnosing techniques that I can use.
Thanks for your help.