I own a 2007 Impala LTZ. Right before 100,000 miles, the car started shifting hard from first to second. I took it to the dealer, who told me there was nothing wrong with the car and they couldnt reproduce the problem. I called Chevrolet and asked if the warranty would cover the problem. They would have if the dealer could identify what was wrong. So, basically I ended up with a bill from the dealer and no help from Chevrolet. Now, three months later the car is really bad and is getting worse. The warranty has run out. I keep getting "starting disabled, service throttle" "engine power reduced" "service traction control" "low oil" , and those are just a few of the many, plus my engine light is back on. Less than six months ago we paid the dealer $997 for repairs, $400 just a few weeks ago to another mechanic to replace something to do with the throttle. Its still running awful, stalls, power is reduced all the time, and dangerous. Im furious because I tried to get it fixed before the warranty ran out. Now Im going to be stuck with a huge bill. Anyone have any ideas about what the problem might be? Any suggestions? We live near Syracuse NY and bought the car from Sun Chevrolet in Chittenango NY.