Well, I could get the Check Engine Light Full diagnostic test done again and to see why that is. Also take your bill from them to a reputable GM/Dodge/Chrysler dealership and see what they can do to help you. Have them do the Check Engine Light Diagnostic test again, and see what codes they come up with. That will determine what your car needs to have fixed and how much.
I had the check engine light come on solid on me yesterday morning and it turned out that the code that my dealership found was the Catalytic Converter...cost me close to $830.00 and that included taxes and parts as well. That was pretty good compared to gas stations and other mechanics who would charge you an arm and a leg for their service.
Be careful of where you take your vehicle to, and always get it done right rather than having more problems down the road later.
Also, this problem happened to me last Tuesday morning my way to work, and it turned out that there was 1 spark plug that went bad. Also, the car needed an overdue Tune-Up and that helped the gas mileage on the car in a big way and the feel of driving it is a lot better for me.
Also, as your GM dealership to see if it could be the Tune-Up...if it is, they will replace the Air Filter, the coils as well as the spark plugs and to tune up the cylinders to have the timing work better on your vehicle. This whole thing cost me $800 or so, but it was worth it. However, it cost me to get the catalytic converter replaced too, only yesterday I got that done.
Hope this helps and good luck.
I have known Jim at Acclaim for years. I have been a tech for 20+ years. You CAN trust him.