I have a 2002 f250 sd it misfires when it warms up at low rpm but it doesn't throw any codes does anyone have any ideas

 

I just had a misfire with my 01 f250 5.4 the issue was #6 coil replaced myself try unplugging your coils one by one if it idles down its good but if you don't hear a change then its bad

 

If you connect a good or decent code reader you'll maybe find a pending misfire code. If that's not an option the process of disconnecting them one at a time works too.

FWIW I installed a full set of Granatelli's COP's that hate the cold---anything below 38* F over night and I'll get one or more misfire codes, the attendant rough idle too. Once the engine is up to operating temp shutting it off for just a few seconds then right back up and rough idle is gone, CEL remains unless I cancel it--which I don't do until spring or summer.

Hope this helps.

 

if you smell any antifreeze with your misfire...check the spark plug hole of the COP that you replace. If you see antifreeze in the plug hole you have another problem.

-your intake manifold like mine is leaking from the coolant crossover tube where the thermostat bolts into.
-or your heater hoses could be leaking.

I had coolant leaking in #6 and #7 plug holes. I have a new intake manifold now, I hope you don't have this problem.