Speaking of Jeeps, my new to me $3500 Jeep took a dump getting on the freeway a few days ago with some loud bangs and I had to limp back home. CEL got lit so I read the codes. Misfire on cylinder 2, bad coil circuit in cylinders 1,2,3,5&6. Five coils don't suddenly fail so I pull the plug on cylinder 2 and it looks like this.
No center electrode and the gap is over .080". Five out of 6 plugs look like this. They're not the original plugs, but they're close and the car has 172k miles on it.
Anywho, replaced the plugs, which undoubtedly caused the bad coil codes, but I went ahead and also replaced the coils, too. They were cheap and we're back on the road running smoother than ever.