That has to do with diesel engine that have D.E.F. injection systems that uses fluid to breakdown exhaust particulates. You can bypass the system and make huge power. Good read here: https://www.hardworkingtrucks.com/exhaust/
For Sale: Pair of RaceStar Wheels in the black finish. 17x9.5" rears. Never mounted, 1 box still sealed, the other opened to take pics only. Comes with RaceStar closed-end lugs for the 15-19 Mustang.
$450 shipped to 48 states. Firm on price as they are brand new. Accept PayPal or cash if you...