2011-2016 Duramax LML 6.6 DPF Delete Kit Race Pipe Exhaust 4/5 Inch for Chevy GMC 2500 3500. Fitment:. 2011 GMC Sierra / Chevrolet Silverado 2500 3500HD 6.6L LMM Duramax Diesel. 2012 GMC Sierra / Chevrolet Silverado 2500 3500HD 6.6L LMM Duramax Diesel. 2013 GMC Sierra /  Chevrolet Silverado 2500 3500HD 6.6L LMM Duramax Diesel. 2014 GMC Sierra /  Chevrolet Silverado 2500 3500HD 6.6L LMM Duramax Diesel. 2015 GMC Sierra /  Chevrolet Silverado 2500 3500HD 6.6L LMM Duramax Diesel. Will not fit Cab & Chassis trucks.. 2015 or 2015.5?. 2015 is a split year. The 2011-2015 downpipe is secured to the turbo-direct pipe using a V-band style clamp. The 2015.5-2016 uses a 3 bolt flange style connection. Be sure to visually verify the clamp style your truck is equipped with.. Features:. The turbo direct pipe on some of the 2015 models has a 3-bolt flange instead of a V-band clamp. These kits will only fit models equipped with v-band clamp and will not work for trucks equipped with the 3-bolt flange off the turbo direct pipe!. The exhaust pipe material is T409 stainless steel. A common misconception: unlike T304 stainless steel, T409 stainless steel is still magnetic. So if you are checking to see if you really have stainless steel, keep in mind that the magnet will still stick to it.. Fuel mileage - Expect a significant increase in fuel mileage. If your DPF is clogged, you probably average about 13-14 miles per hour. More or less depending on the degree of clogging. After removing the DPF/CAT, expect a combined mileage of 18-19 mpg. Big tires and poor driving habits will result in lower mileage.. Exhaust Material: T-409 stainless steel. Unlike T-304 Stainless its still magnetic. So if your testing to see if you actually got stainless; beware that a magnet will still stick to it.. Thickness: 2mm. Inlet Diameter: 4"/5". Installation:. Install takes about 1hr with basic hand tools done on the ground of your driveway or garage. Quicker if you have automotive style lift. Cutting may be be required to fit shorter wheelbase bed/cab configurations. Clamps, hangers and hardware are included. You may have to re-use some factory hardware.. Tuner required. Removal of DPF, CAT, SCR and/or DOC includes removal and elimination of emission related sensors. A tuner with DPF removal capability is required to prevent engine warning lights or diagnostic trouble codes.. Benefits: Expect to see a significant increase in fuel mileage. If your DPF is plugged up your probably averaging about 13-14 mpg. More or less depending on the severity of the restriction. After deleting the DPF/CAT expect to get a combined mileage of 18-19 mpg.. It removes the need to service the DPF at regular intervals (cleaning, replacement). A DPF delete will remove the possibility of a DPF failure which could cause expensive diesel repairs. Due to less exhaust backpressure, the DPF delete increases exhaust flow and therefore increases the performance of your motor!. Paired with an ECU remap, the DPF delete is proven to increase power and torque for all vehicles