I have a 2003 matrix XRS. VVTL-I. 6 speed manual. My idle goes up and down from 1800 up to 5000 RPMs at times. Only happens when it’s in gear it’s weird because you can kick it down like an old-school carberated engine. have changed the idle air control senser, cleaned the throttlebody checked all the air hoses for vacuum leaks, air filter and box. .... been screwing around with this thing for months and months. No one else will drive it - they say it’s possessed. I think it is Lol. .its not throwing any codes ? It seems mechanical more than computer because you can kick it down Any ideas ? I absolutely love my car but it’s going to kill me one day It wants to go when I need to stop or slow down.