I didn't drive my car all day (99 g20) went to pick up my gf and passenger noticed my mph wasn't moving looked over and saw the rpm wasn't either odo set back to 0 fuel was "full" even thoe it wasn't temp was high then the odo changed to 9999999 and rpm and mph were kinda working it wasn't accurate I was going maybe 45mph and it showed 20mph I'm thinking its the computer? please help its my daily driver to school and work