My ODB II reader arrived today so I was able to extract the fault code from the ECU.

The code I got was P0304 which is misfire on cylinder number 4.

So please explain to a divvy like me what the most likely causes of this would be and what I should do in order to rectify matters.

My first thought was to check the plugs, which I haven't done yet as it is pitch black out there.

Any other ideas ?

Thanks in advance.

 

See link in my thread.

Normally plugs / coil pack / injector / MAP sensor.

Can also be engine related.

If its a code which has been repeating you can systematically move parts (injector / coil / plug) to a different cylinder to see if the code follows.

 

Cheers Mark, I'll go through all the obvious points in your thread.

I do have Denso plugs fitted so I'll whip them out ASAP and have a look at them, in fact I'll order some NGKs tomorrow.

 

Good plan!

 

I had misfires on cylinders 2 and 4 two weeks ago - turned out to be fouled plugs (too much oil at Rockingham track day is the likely cause).

 

Does anybody have the part number for the NGK platinum plugs ?

Just seen this on one web site and it looks like the right serial number from memory, can anybody confirm this ?

PFR7G-11S

Cheers.

 

Yep thats right.

There is an iridium part number too BR7IEX or something.

 

Which can be ordered from the website linked in my sig

 

Cheaper on Ebay.

Just ordered 4 x PFR7G-11S this morning and received an email confirming they have already been dispatched.

Total cost was

 

Are these the OEM ones? Or they are better? Does anybody know if is the same NGK plug code for 2004 models?