Hey, I had to pull my jackass buddy out of the mud because his jeep couldn't make it, and as soon as I got him out (4lo and 1st gear, no more than 3k rpm) my CEL came on but it ran alright. As soon as I got on the highway, however, it started to run like crap below about 2k. 60mph and 3rd gear though it runs like a champ. When I hit a bump, the light blinked off and on. I pulled the plug because I got p0308 (cyl 8 misfire) and it looks just fine. What's up?

 

could be a number of things, reset the computer and see if it comes back, could just be a weird thing going on with the computer

 

Nope, cleared the code and it came right back. I can definately feel it too.

 

compression test?

 

check your cat might of broke it just a idea

 

You cant drop a valve seat, however you can drop a valve, but that isnt the first thing I would go to.

 

I would definately do a comp test on it... you should have cats right off the e-mani collectors... if the cat is clogged (like mine was) it'll put alot of heat on the # 8 cylinder (like mine) and the exhaust seat will fail (like mine). I yanked the head, took it to a shop and had them fix the one cylinder. cost all of $40 bux for their labor. about another $75 in gaskets (including the plenum) to put it back together. start with a comp check then if you have the tools, do a leakdown test with compressed air... if it's the exhaust valve you'll hear air in the exhaust mani...

 

Bad spark plug wire, corroded dist cap terminal, plugged Injector?