I have had my car in the shop 5 times because it turns over but won't start. The very first time they said the fuel sensor was bad, replaced however said the flex fuel compensation sensor was also bad but was not covered under extended warrenty and my car would run forever without replacing it, just would not pass emmissions. I did not replace it. Two weeks later car won't run again they replace the fuel pump, one week later car won't run again they replace a relay switch, 3 weeks later car won't run again. Bring it back to the original place that has been repairing it. They say now it needs a tune up, the wires are bad because they pulled them and broke them. Have them send it to the Chevy repair place who tells me the flex fuel sensor is bad and it is flooding the gas making the car not start! I have driven this thing for over 6 months with these issues after the original shop told me the flex fuel sensor was bad. If it was the sensor why has it been running up to three weeks and then not starting??? If I thought it was the sensor for absolute sure I guess I would replace it for 900 bucks, but I feel it is just another guess.