Ok so I have a 2015 f150 with a 3.5 TT. If you only use about 1/4 of the pedal it will drive fine. If you try using more than that it will start to stumble and will throw a misfire code, engine only has 135,xxx on it. Has anyone else had this happen.

 

What code(s) do you have ?

 

It's telling me that #6 is misfiring. I don't have the exact # in front of me at this moment.

 

Sounds like you probably have a P0306 Misfire Cylinder #6. Swap parts until code moves to another cylinder. Start by pulling Coil On Plug (COP) for cylinder #6 and exchange (swap) it with another convenient cylinder's (example #5) COP. Keep track of what you are moving around by marking it with a marker pen or piece of tape. Erase codes, then start engine and see if code moved to cylinder #5 and if the code moved you have found the problem COP. If code stayed the same then swap #6 spark plug with (example) #5 and see if code moves. If required swap injector #6 with (example) #5. Make sure all connectors "snap" in place when reconnected. This method eliminates one thing at a time and points you to the problem area.

Note: COPs rarely fail but the rubber boots fail more frequently.

 

Double check the COP wiring as well. Critters are known to nibble on wiring from time to time.

 

oretty sure that would be a different code though (why it’s always good idea to post actual code numbers and description).