Hi Guys and Gals,
Thought I'd put up my quick story. *Edit in real life we're talking 6 months diagnosing* I had an intermittent misfire. Cylinder 3. It was getting worse and worse and less intermittent. Error codes etc. Moved to other cylinders. Cylinder 5, then various ones, then all of them.
Mechanic threw plugs, plug gapping, new coils, new wiring at it. Nothing. Then I asked him to replace Fuel filter, it was terribly clogged. All misfires disappeared, no new codes. Unbelievable.
Moral of the story, a misfire could be for about 647,000 different reasons, luck of the draw, I was lucky I suppose.