i know mines original and just about every day after a short ride in the morning to my local wawa after i hop out and grab breakfast and hop back in the rpm's jump up to 1,500-2,000 and i can't kick it back down, i have to put it in gear for it to stop. no codes and she"s well maintained. my cat's 02 sensor was original and never threw a code and it was def bad. car had like 250 on her b4 i finally realized that had to be one of the reasons my car was failing emissions.

 

have u tried adjusting the TPS ****?