I have a 2000 GT. It starts just fine but when you go from a stop it stumbles. It stumbles until it gets up to about 45. Runs fine after that. Going up inclines it lacks power and stumbles a lot. The SES light comes on and flashes then goes off. It is on now, the code is P300. I've looked over everything, nothing seems to be wrong on the surface. I've got new plugs and wires I'm putting on. Recently changed the air filter, fuel filter, and pcv valve. Scratching my head.