I just recently got a cobalt ss sc at a used car dealership for a good price, 55k miles, and it runs good, except for wide open throttle. It seems to hesitate or lag if you will, like the engines getting too much or not enough fuel or something. It has an aftermarket fuel pressure regulator from summit on it. I don't know that much about fuel ratios but I'm mechanicly inclined. Could someone point me in the right direction?