I have a 2007 Subaru Legacy 2.5. It runs well but if I accelerate harder than normal the check engine light/cruise light comes on. I find a 303 and 304 error code. Car has new plugs wires and coil plus a new timing belt. Idle is fine, starts perfectly and runs around town for my wife just fine. Problem is if I run the RPM up a bit higher the lights come on. If I erase them they will stay off until the next time I push it. Ideas?