i have replaced the camshaft sensor, both o2 sensors, and the coolant temp senso on 2003 Mazda Mazda6

and the codes po340 and po128 keep returning. the engine surges a little and at hwy miles mph 65 to 70 the rpms go crazy but nothing major drivibility wise. can someone please help???

1 answer
seek diag you may have a circuit issue