I just purchased a 2013 F350 super duty 6.2l dual fuel CNG/Gasoline. I am getting a cel and code of miss fire on cyl 7 intermittent. i have been running the tank of gasoline down with some additive to put some fresh known gas in it for a baseline. the miss fire is getting somewhat better but is still there. the truck has 138000 miles on it and the records indicate the plugs are original,so i thought a new set with wires would be in order also. does anyone have any advice as to what type or brand of plug works best in my truck? thanks

 

Motorcraft plugs.

 

Motorcraft... should have been done at 100,000. wires also.

16 plugs and 8 wires.
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yes i agree that the service is long overdue. my main concern is if there is a preference for plugs that work best with CNG or LPG. the engine is a factory westport CNG conversion but i don't know if they call for a different plug and my dealer doesn't know either. i was just checking to see if there might be someone with more experience on this forum. i posted this on the alternative fuels forum first but there is little traffic there.

 

Very interesting question, I don't know much about CNG conversions.

Remove one of the plugs and take a look. Should take about five minutes to have a solid answer.