Misfire problem solved!

[AJR182]

Discovered a misfire a week ago, EML light flashing and the car was running rough especially on idol, so after scanning the car it wasn't being very specific, code P0300 (misfire cylinder/cylinders) so this was a start.
After reading up on here, most people changed the coil pack, leads and plugs so this was my port of call. Looking at the spark plugs 1-2-3 looked ok but number 4 (cylinder 4 nearest drivers side) was loaded with carbon, which lead me to think injectors.
After rescanning the car a more specific code of P0304 came up which confirmed cylinder 4 was at fault. Next stop new injector which I bought and fitted, swine to get the fuel rail off but advise on here saved the day.
Just back from a good run out and all is well, apart from being £160 lighter lol. But a great feeling knowing it's all working sweet.

 

[pj_sibley]

Well done, great result! Nice to hear about some logical, evidence-based diagnosis taking place :up: Proves it can be done DIY with simple diagnosis equipment and use of the forum.

 

[AJR182]

Thanks buddy, I just wanted to post the results in case anyone else had similar issues. People have kindly put things on here and just thought I would pay it back.

 

[pj_sibley]

As it happens, I was interested because I had exactly the same issue and handled it in the same way :smile:

 

[AJR182]

The misfire is back again, just bought the pre cat O2 lambda sensor. Fingers crossed its that. Will fit it ASAP.

 

[AJR182]

 

[bb55am]

pre cat lamba has been the culprit twice for me, 3rd time was corroded pins in a connector block, 4th time a trapped ht lead, 5th time a full bottle of redex injector cleaner sorted it.

 

[AJR182]

Will also try the Redex, thanks for the tip bud. I did change the P0304 injector along with all new leads, plugs and Cpack but the misfire code still appears (flashing EML). Would a shot O2 sensor bring the misfire code up? I would have presumed it would be its own code.