My car started running like crap when it started getting really cold. Mostly Misfiring bad on cold start up and a bit on warm restarts. Then I threw a CEL with DTC Code P0302 Misfire on Cyl 2. A few days later the light went out but it was still running like crap.
My car has 77K on it so it was time for plugs, wires and fuel filter. I replaced the plugs and wires and it runs great again. Perhaps better than ever since I've had it. Problem solved, but.....
..... I am a bit concerned with the plug from Cyl 4.
As you can see from the pic, there appears to be some kind of corrosion or some other gunky build up on the plug. Should I be concerned?