I have a 03 PR5. On day it decided not to start on me. After getting it towed we figured it was the fuel pump, so we replaced it. (Th battery was repaced as well). It would start up then cut off. Over the past few weeks, the water pump, timing belt, egr valve, spark plugs and wires have been replaced. The car would start hard, idle really low but drive...kind of. From stop to go it would feel like it was about to cut off. It was very jerky and to be honest scary to drive. After taking it to a mechanic he said that it was my head gasket. So after replacing that, the problems sill exist except for now my car wont even stay running unless you keep your foot on the gas. After that it will cut off again. Does anyone have any ideas what we could be over looking? I hope I gave enough information, can provide anything else if it helps. Thanks.