Hi,
I own a 2005 Honda Element and I had a P0303 trouble code originally. Replaced spark plugs, ignition coil and fuel injector, had valves adjusted and was told it was probably a burnt valve. So, decided to take the cylinder head off with a load of help from my dad. It was definitely a burnt valve - had the cylinder head machined and all the exhaust valves replaced and finally got the whole engine back together again (I can certainly understand why the dealership wanted so much $ to do this job!). So, the car started right up (yeah! I was worried since I'd never tackled a job like this before) but before I had even driven a mile, the MIL came on again. Oh no! This time the DTCs were P0300, P0302 and P0304. So what did I not do correctly on my reassembly? Any ideas? While we had the engine apart we replace the water pump, the thermostat and the drive belt.
Thanks for any suggestions!

 

Hiya,

Have a look at the information below.

P0300 - Cylinder Misfire Detected Random Cylinders
P0302 - Cylinder 2 Misfire Detected
P0304 - Cylinder 4 Misfire Detected
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
Tech notes
The P0300 / P0302 / P0304 code means that a cylinder(s) is misfiring or is randomly misfiring. 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. If the problem persist more tests needs to be done to diagnose problem, see "Possible Causes"

Regards,
Kev

 

Thanks, Kev!