P304 Cyl 4 misfire

[alloy6ix]

What would cause this? It showed up on my wifes 08 4.0 a few days ago. I checked the code and came up with that, I cleared the code and then checked to see what would happen. The car sounded so rough at idle, I thought someone had snuck a crower cam in there!! but... after I cleared the code, the car ran fine for about a day. It came back again today, and now I'm at a loss.. Anything I can do or check for before I just have to drive it to the dealer? i think there was a thread with this exact code listed a while back, but used the search button and couldn't find it. thanks guys.

 

[aeraceranthony]

Take a look at the spark plug and spark plug wire. It might be a cogged injector but doubt it. It will more than likely be a fuel or spark issue. You can always run some fuel injection cleaner to help (Lucas works great).

I would just take it in, warranty should cover it. Less headache.

 

[alloy6ix]

true, but her dad would rather take it in to another dealership where I know they are a pain in the ass to do work on cars. That's why If I can do it myself, I'd rather do that. lol.

 

[aeraceranthony]

Did you get it fixed?

 

[alloy6ix]

yeah, actually I did. Exactly what I did was turn on the car. Code was still there. checked the owners manual, it said check the gas cap as well. I checked and cleared the code, opened the hood, checked the air filter, check the spark plug wires, everything looked fine, made sure the gas cap was tight and turned the car on at it was fine. Code hasn't been back since.