I changed out my throttle body the other day but of course got the angry wrench light. I made sure the TPS voltage was within the 1.19-1.31v range. The car started but sounded like crud and died. I'd then recheck the TPS voltage, but it would be substantially different than what it was at before the car was started. So, I changed the TPS. Now it idles better, but I still get the angry wrench and hitting the gas pedal barely makes the engine rev at all. With the engine idling, I checked the TPS voltage, and it drops down to just under 1.0v. What could be causing this?