'99 2.7L CEL is now on steady and code 0300 is showing. Used to read 0303 some of the time. I've changed all the plugs, swapped coil packs and checked the wires going to the injectors. New IAC motor. The car is rough at idle but runs just fine at road or highway speed. Just at curb idle it is rough running.
Any ideas on what to try next? Just had an oil and filter change. The throttle body was cleaned at the dealership about 30000 kms ago. I run Seafoam through the intake and gas tank with no help.
Engine was rebuilt last year. Suffered the dreaded spun bearing. Total rebuild performed and all new parts put in at that time, water pump, tensioner, timing chain etc. From what I have been reading in other posts it may be a cam poistion sensor or crank position sensor? Is this possible? I already replaced the IAC motor for nothing, can't return it.