Fuel mileage still sucks

[tree98]

A proper demandate eliminates the function of all emissions components. You'll want to get in contact with runningrough here on the forum to have it done correctly.

You will have to take the cans off the truck and hollow them out COMPLETELY, that means ALL of the honey comb stuff in there, you don't want anything left behind that can break loose and cause restriction later or anything that can reflect heat back upstream and damage your turbo.

Really the only thing you need to block is the EGR crossover tube coming into the intake Manifold. You could just take the tube off (not hard at all) and have a welding shop weld it up water tight with some 1/4" plate and you'll be good to go, that shouldn't cost more than around $50.