i have a 96 grand Prix SE 3.1 v6 the car seems to run fine when cool then the car gets up to running temp it starts to sputter and jerk the rpms jerk up and down then the car dies ..i can start it up again but sometimes is just dies soon as i give it gas. the car doesn't over heat or anything..it will idle just fine ..also when it starts to get to running temp it sounds like its crackling..the cat converter doesn't get red hot or anything when it acts like this either..i have changed the fuel pump and fuel filter..also changed the MAP sensor and checked the vacuum pressure and seems to be fine..i was searching on the net and i come across the coolant temp sensor and bad fuel injector and they seem to have the same symptoms i don't have a ohm meter to check the injectors or anything..when i took it to orielys for a scan the code came back EVAP canister purge valve but the guy said it wouldn't make the car run like that...im at lost and have a vey low income to be guessing on whats wrong and spending money when its not the problem would be very grateful if someone could help me out please!!