poor mileage,black smoke

Have you been to a cat shop and had the injectors ck. May have 1 or more over fueling?

 

Sadly most dealers are clueless if everything hasn't been left in stock form.

 

Do any of you use that additive you put in the fuel to help keep injectors clean?

 

We haven’t used it on our truck but was wondering if maybe we should. We have a 2016 Pete.

 

Personally inthink a little fuel additive is good now and then. Fuel is so dry a little extra lubricity is good. I run 2 stroke oil every now and then, not sure if that would be okay with an emissions truck.
As for the original post, check turbo and piping for leaks. Changed air filters or fuel filters? And cat refusing to look at it because it's been altered? What a crock of poo. A different turbo and tune on a pre emissions engine gimme a fricking break, procedure is still the same. That really ticks me off. I could understand if it was an emissions motor that had been deleted but a 18 year old pre emissions come on

 

I like my cat engine but absolutely despise cat dealers

 

O yea a slightly clogged air cleaner can make a lot of smoke, charging it out with a new one is 1st step?