Recently the engine service light came up with code P0300 multiple misfires. I used timing light to pin point which cylinder wasn’t firing and came up with #4 and #8. So I checked wire for resistance and plugs seemed to be fine. In addition I replaced both coils and I still have multiple misfires on #4 and #8. my next step would be?
Chevy Code P0300 – Cylinder Misfire Detected Random Cylinders
The P0300 code means that a cylinder(s) is misfiring or is randomly misfiring. Therefore , start by checking for intake leaks, intake gaskets are common caused of multi-cylinder misfiring. If no leak are found the next step is to replace the spark plugs. In conclusion if the problem persist more tests needs to be done to diagnose problem, proceed to “Possible Causes”.
P0300 Possible causes
- Faulty spark plug (s)
- Faulty ignition coil (s)
- Clogged or faulty fuel injector (s)
- Intake air leak
- Fuel injectors harness is open or shorted
- Fuel Injectors circuit poor electrical connection
- Ignition coils harness is open or shorted
- Ignition coils circuit poor electrical connection
- Insufficient cylinders compression
- Incorrect fuel pressure
There is a factory Technical Service Bulletin on this Vehicle for Code P0300: TSB#03-06-030F