When this first started being a problem, my 2008 G6 GT went into limp mode while driving home going about 45. Luckily, I had my friend's code reader still in the car so I ran it and came up with the P2135. Also luckily, I pulled over really close to an auto zone. I call my dad to tell him what happened, we read up on what the problem is and assume that replacing the throttle position sensor will solve the problem.
It did, for about a week and a half. Then my car went into limp mode again. So the next thing my dad and I did is clean the throttle body itself. That didn't solve the problem either. I found out if I turn my car off for a few minutes and start it back up, the check engine light will still be on but it won't drive around in limp mode, allowing me to get home or wherever I was driving.
Doing that little trick worked well enough while my dad and I tried to figure out what the next move would be. It was 2 weeks until it went into limp mode again. Then one week. Then every other day. Now I can't drive my car without it going into limp mode twice in one trip!
My dad and I have been trying to fix this issue for about a month now.
I guess what I'm saying is I don't know what to do next. Replacing the sensor didn't solve the problem and I have a feeling replacing the whole thing won't solve the problem either. I don't want to take it in to a shop just yet because maybe the solution is something simple that we haven't tried yet. What are your thoughts?