2003 Disco - Service Engine Soon light on

[dtrasatt]

I have a 2003 Discovery Series II with 60k miles. The Service Engine Soon light came on. I took it to Auto Zone and the code is P0304 (Cylinder 4 misfire). The car is running fine with no perceptable issues. I did install Bosch Platium 4 spark plugs about 6 months ago. I also put in a fuel additive to clean the engine last time I filled the tank. The water pump and the head gasket were done about a year ago.

Any advice would be appreciated.

 

[Disco Mike]

You should do the full 60K service at some point and replace the plug wires now, which are causing the problem. Make sure to use an 8mm wire like Magnacor or STI.