Misfires when using manual mode

[flanative3]

I'm not sure why, but anytime I use the manual gears in my '13 3.5, the check engine light comes in and the error codes are always for cylinder misfires. Does anybody know why this happens?

 

[1995E]

What is your mileage? If it’s high, check your sparkplug gaps. If you have the 3.5L Ecoboost, you might have carbon build up in the valves.

 

[flanative3]

It has 135,019 miles, and it's the regular v6. It might be the spark plugs like you said, I don't think anybody's checked up on the engine since it's been in my family.

 

[blwnsmoke]

When you are using the manual gears, are you letting it rev up higher then you normally would when it is shifting on its own?

My thought was yes and it could be a high rpm issue (spark or fuel issue).

 

[flanative3]

Don't usually let it above 3500-4 rpm, cause that'll definitely put some wear on it. Whenever I go to the dealership to have the recall on the power steering done I'll probably ask about it.