My Check Engine light was continually coming on and I discovered that if I unscrewed the gas cap and then put it back on the warning light would turn off. I went to visit my family in Spring, Texas and I took it to an auto shop for an oil change before I was due to head back home to Montana. The mechanic told me the Check Engine light was on because there were THREE problems with my car...PROBLEM ONE-Serpentine Belt needed replaced (I got that replaced). PROBLEM TWO-Throttle Body Cleaning (I got that done too). And PROBLEM THREE-Needed EGR Replacement. I've had FIVE (5) mechanics tell me they didn't believe the Valve needed replaced. They all say that it sounded to them like it just needed to be cleaned, something about carbon buildup that need cleaned. I had to come home to Montana and my car is in Texas, so I have no idea what to do.