OK, I replaced the plugs(motorcraft), replaced the DEFP sensor (code 1405), cleaned the MAF, IAC and throttle body. Runs a little better, it actually ran better before replacing the plugs. I don't know what to do next. Maybe the COP's are bad??? Vaccum lines are ok, replaced the PCV valve also. Any suggestions?

 

is the gap correct?

 

set the gap to .55 within the specs.

 

Try some techron fuel additive or techron fuel (Texaco/Chevron) and see if that helps. Maybe you have some carbon spots on the valves or combustion chamber and with the new plugs, they are burning so efficiently that the smallest blockage will be noticeable.

 

I'll try that, I did put some B12 in the tank. I'm gonna burn that then I'll try the techron.

 

That might be the cause then. As it's burning through, it's actually increasing the octane of the fuel with the additives. That higher octane is harder to combust thoroughly for N/A engines (and lower compression engines) which will make the truck/vehicle seem like it's ******* a bit. Try a full tank of regular next time and see if it improves......it should.

 

thanks, I'll give it a try. If the plugs were misfiring, mt CEL would come on RIGHT????