hello. I am new to the site so bear with me. I have recently purchased a 2006 Grand Prix GT and it has some issues, or an issue. The service engine light is on and the car seems to have an issue going into 2nd gear. I have a Buick Century that had the same issue but there was a wire with a hole in it and that fixed that issue. I have changed the plugs and wires but its still the same. It seems like it may be the fuel injection or an O2 sensor, I think this car has 2, but I am not sure. I know a little about cars but not a lot. I don't like taking cars to shops being that I am a woman and they try to tell me all kinds of things are wrong, so i try to get a general idea of what to ask for. Can anyone help me with this?