Check Engine Light? Truck Reduced Engine Power or Stalling - Code P2135 If you have noticed that your engine is weak, your vehicle won't accelerate well, it stalls out, or it has entered limp mode (the engine cuts off at low RPM), and a check engine code P2135, you have a problem with your throttle body position sensors. Unfortunately, you will have trouble driving your vehicle until the problem is resolved and the code is cleared. Watch this video to find out how you can diagnose the problem, a