I have a randon cyl 1 misfire. Only at idle though, while driving it runs and drives as smooth as a new car. I get the intermittent CEL for a code P0301, sometimes while at a light you can feel the misfire pretty good, sometimes it idles fine. It never loses power. Plug was not fouled, it was clean and the same color as the other 5. Bad injector? if it were a valve wouldn't it be a constant misfire?

 

I too am interested in seeing the responses to this, as my Jeep started doing the exact same thing a few days ago. Cylinder #1. We made sure it has power to the injector, just not sure if its an injector or something worse. Mine seems to do it (at least slightly) above idle too, but you can't feel it when driving..

 

Ok I have something very similar to both yalls problem. A random cylinder 1 misfire. I started out with changing or cleaning all the small and least expensive parts. Nothing changed. I finally done a compression check on all cylinders. Cylinder 1 was at 90 psi when the adverage of the remaining was 160. So I have a leak somewhere in cylinder 1. I am pretty sure I have a burnt vavle. I still need to do a wet compression check and a cylinder leak down test. I am just going to remove the head have it inspected, cleaned and maybe a valve job.

So my recommendation is start with a compression check. Dry and wet. I didn't do the wet when I did the dry bc for some reason I couldn't find any oil around the house. ThAt's the first. Let us know what the results are. I have also noticed a big drop in mpg since I started getting the ce light