2019 v6 Misfire/poor mileage

2019 v6 access cab, tuned, 33s, 52k miles

I did a long trip over the holidays and where I would normally get 19-24 mpg I was struggling to get 14/15mpg. No wind or anything, and same cruising speed.

I hooked up my OBD and pulled up torque, there were no freeze frames no codes thrown.

However, after poking about I noticed that there were roughly 40+ misfires within the 2 hour drive, all of which occurred on cylinder 3. You could fell it missing. I remember reading about one of the cylinders on these engines having issues but was unable to locate/search for which cylinder it was.

My plan is to check the plug, then swap the coil pack and see if the misfire moves/is eliminated. Alternatively I have read that cyl 3 issues may do to a part in the intake breaking off and resting on cyl 3 valve.

Thoughts/advice/any other info seen about this?

 

I have not encountered this issue personally. But, I have read a few threads that mention the crank position sensor and/or loose spark plugs, as contributors to the symptoms you are describing.

 

Spark plugs are due at 60k miles so maybe yours decided they wanted to go out a little early

 

Check the torque on that Cyl 3 sparkplug. Very easy to get to. I had the same misfire code, because of it. Actually, I had a whole lot of stuff wrong with my truck (broken ACIS shaft in the plenum) which caused all kinds of misfire codes and failed coils... finally got resolved.