Hello, I have been having problems with my sunfire, it runs fine when it's cold but when it warms up I start having problems. There will be a rough idle(a thumping sensation in the engine) and it will hesitate upon acceleration. I went to autozone and they ran the diagnostics and it says: Heated Oxygen Sensor, High voltage, and Cylinder misfire in cylinder number 4. I have replaced the fuel pump, fuel filter, distributor cap, temp coolant sensor and BOTH Oxygen sensors. So, I don't know why the oxygen sensors are still showing up on the diagnostics, as I just replaced them. What is going on?!? What is causing the engine to misfire? What do I need to replace!? I don't want to keep putting money into parts that I don't need. Thanks so much for your help!
Okay, So what's with the heated oxygen sensor and the high voltage??
Okay, So what's with the heated oxygen sensor and the high voltage??