Have a 2007 F150, 33,000 miles, got the oil changed, went on a trip pulling the camper, misfired pulling load up the hills, and letting off the gas coming down. Gas mileage horrible. Got home, code reader says random misfire, and all cylinders except 3 and 6 misfired. Have not tackled changing the plugs yet, pulled the COP's, all look good. Engine light on, otherwise, runs great when not pulling the load. Any ideas? thanks

 

How can you tell just by looking that the cops are good?

 

Sounds like a Plug, Cop or injector issue. If its only doing it on load I would say you have a plug or COP that is fouled.

 

Those were the symptoms my truck had at 60k pulling a bass boat when the plugs were going. 115 bucks and 2 hours later she's never hiccup'd since.

 

tha

 

Thanks, plugs and COP replacement are next. Not a cheap process is it? Keeping fingers crossed for no problems. Thanks for the suggestions.