I had a problem with my Celica that kicked my %^$#. I bought this car in August, It had new timing belt, plugs, wires, rotor and cap. Car ran great then my daughter told me her Auto transmission was slipping by the end of the day it barely ran. When I got to the car it started and ran good and drove good....cold....when the car was warm and in neutral or park ran fine but as soon as you put it in gear it wanted to die. It would drive as long as you didnt give it alot of gas but as you drove it it would keep getting worse till it would die constantly! After going through the whole vacuum system, checking plugs, compression checks....a week of troubleshooting.... It was two plug wires arching...each had a tiny hole in them! new plugs and wires and it runs great again. I hope this helps someone!