P0304 & P0514 DTC(s) & other symptoms

[MSkyrman]

Greetings,
My engine is (mostly) running smooth, just got back from a 1,200 mile road trip, except when at a stop and truck is in drive the engine seems to idle roughly and there is increased vibration. I think the rpms when stopped are around 3,500 to 4,000 rpm. This morning it threw a code P0304 - Cylinder 4 misfire. Before that it pulled P0514 - Battery Temperature Sensor Performance/Rationality. My batteries are 7 years old, and may be getting weak, approaching winter I was thinking of replacing them. Is there a chance that the state of the batteries could somehow be related to these codes/symptoms?

Thanks

 

[Topzide]

Batteries seem to throw gremlin codes a lot! if they're of that age, I'd replace them. Have you had them on any type of trickle charge through their life span? Check the standing battery voltage with cross-over cable removed. Let the sit for a period of time (24-48 hrs), then check voltage again. If it's lower then a couple tenths then before, they're in need of replacing. 7 years is a good run on a set of batteries. Let us know how it goes so that others can learn from what has happened to you.

 

[MSkyrman]

I replaced the batteries which I think was prudent heading into winter after getting 7 years life from them. Didn't solve the code throwing and rough idle symptoms I was encountering. Turns out 3 injectors were failing. I replaced with new bosch injectors and replaced fuel connector tubes and boy, the truck sure does run smooth now. Kinda stung forking over $4k to the shop on a 2003 truck with 215k miles but hopefully will be good to go for a good long while on the motor at least. The rest of the truck may fall apart, but the cummins will still be running. Ha!