P0304 engine code

[Buffalo]

2002 gas 3.0 4x4

Sometimes it has a rough idle and the CEL will flash, but once it's moving the CEL goes off.

The CEL has come on and stays on now. It throws a P0304 code, cyl 4 misfire. Plugs and wires are about 20k miles old.

Any ideas on where to start? I had service manuals, but they were stolen in the last break-in. I cleaned the MAF, but it's no better.

 

[Rearanger]

Any ideas on where to start?

Basics; hot compression test, inspect color/condition of plugs. Maybe switch an ignition wire (keep timing order) to see if misfire moves.

 

[NIPs]

U have a plugged cat, when ur cel begins to flash it means cat ur is about to fail this usually happens becuz of a misfire and the raw fuel thats not being burned off from the combustion cycle are melting the cat, that engine I think has 2 cats 1 for each bank check them both

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