I have a 2001 with a 5.9 in it and twice in the last 2 weeks it has showed a P0305 code. 4-5 days after the code shows, it goes away for a few days. Is there something that could be throwing this code? I am not doing any rough or off road driving when this happens. Just normal city driving.

Any help please...
Thanks

 

PO305 stands for misfire in cylinder #5. When was the last time you changed your spark plugs, wires, and/or distributor cap/rotor?

 

I just bought the truck and the guy said that he changed the plugs about 6 months ago. As far as the wires, cap and rotor I am not sure... I dont remember what he said.

 

Generally all of those are done together (or at least plugs and wires). First thing i'd do is make sure #5 (should be drivers side 3rd one back) spark plug wire is pushed on there nice and tight (both at the plug and distributor end) .

If it continues, I'd pull that plug to see what it looks like and go from there. Possibly inspect the wires to determine their age (though thats always more of a guesstimation) to see if the previous owner replaced them with the plugs or not.

 

Checking threads on this as I'm experiencing this AGAIN! Other than cylinder heads, the truck just received all new components - cap/rotor/wires/plugs, plenum repair & mod, water pump, timing set, new front O2 sensor, dual exhaust, spectre CAI and I run premium with Superchips programmer. It was running fine, now getting P0305 code coming up. I will clear it and it will run for about 1-2 weeks then come up again. I've dumped so much money into this truck after a new tranny - what the heck is it now?

 

Swap injectors for cylinder five and seven. Clear the PCM, and drive it. See which cylinder comes up with it next.