Need help with my 96 mazda mx6 M edition. I recently had a p0304 misfire cylinder #4 show up on me while driving. I looked it up and did most of what is was say like check spark plugs/wires so on so forth. I have been working on this and after replacing parts and resetting the code it will pop back on after driving the car for less the 10mins. I have checked for any vacuum leaks and cant find any and all seem to be fitting nice and tight. Idle is rough once the car starts warming up. The start up of the car is also rough and hesitates to start. I have replace the following parts for the car. Spark plugs and wires, new disty cap and rotor, PCV valve, and downstream O2 sensor that a mechanic told me was the problem. If any one has any ideas on what this could be would love to hear it.
No, I have change that and a new rotor, spark plugs and wires, with a new o2 sensor. any other thoughts I have now vacuum leak tests and cant find any. I have even sprayed carb cleaner around to see if RPM would jump up and got no response. thank you.