misfire in cylinder 4 on a 6 cylinder jeep grand cherokee 2001 HELP! PLEASE!

The white substance is most likely a dielectric compound - good stuff. The fire triangle: Fuel, heat and air. Injector, spark plug, wire, cap, compression, lifter, rocker. I'd look at the fuel delivery (injector) - is it getting power and does it work?. I'd also look at compression in this cylinder versus the other cylinders (valve problem). I wouldn't drive it until I got it fixed. Could damage the Cat if it's dumping a lot of unburned fuel.

I have a Jeep Cherokee 2014 and I been having the same misfire problems. My car tends to bark every time I start it or even when am trying to stop at a set of lights... Took it to the dealer and they’ve replaced the cylinder heads, camshaft and coil... I mean, almost everything they thought would have been a problem... They were even thinking of changing the transmission but I said no because they’re not sure whether it’s the problem. Every time they fix it, the check engine light keeps coming back on and it’s clear they don’t know what the problem really is! I was advised to call crystler company to see if they could be of help but it was in rain effort. It’s costed me a lot of money and time! My mechanic told me that this is a common problem with Jeep’s and had I known earlier, I wouldn’t have gone for it!