Hello I'm new to this site and I have a 2006 Grand Prix base model my car was leaking trans fluid because the previous owner out way to much in it(just bought it Saturday) and so I did a trans service and oil change went to go test drive the car after I filled everything up and now it barley runs my check engine light is on and my reduced engine light is on the previous owner had a junk yard motor in and a new gas pedal Assembly put in and it was running fine before I did the trans service what could it be