Just changed the timing belt on my son's 2003 3.2TL. After completing, I took it for a 3-4 mile drive. It ran rough while changing gears (auto trans.), so I took it home. It threw me a P0336 code and now will nor re-start. It will try to start...sputter, shake, and cough, but will not catch. What is going on here? It ran great before the service. Please help!