The MBRP S6208409 (Armor Plus / XP Series) is a heavy-duty 4-inch cat-back single-exit exhaust system engineered for 2003–2007 Ford F-250 and F-350 Super Duty trucks equipped with the 6.0L Powerstroke diesel engine. Fabricated entirely from 16-gauge T409 stainless steel tubing, this system delivers superior protection against rust, road salt, and harsh weather conditions compared to entry-level aluminized steel. Designed to bolt directly behind the factory catalytic converter to keep the truck 50-state emissions legal, MBRP outfits this XP Series package with an intermediate extension pipe, a spiral-louvered high-flow performance muffler, an over-axle tailpipe, OE-style welded hangers, and an angled mirror-polished 5-inch T304 stainless steel exhaust tip.

High exhaust gas temperatures (EGTs) while towing heavy trailers, power-choking backpressure from restrictive factory 3.5-inch tubing and dense OEM baffle mufflers, sluggish turbo spool, and rust-through corrosion from winter road brine are what this system cures. The factory Ford 6.0L exhaust pinches airflow downstream of the catalytic converter, causing thermal energy to back up into the turbine housing and cylinders under heavy load. The MBRP S6208409 opens up exhaust evacuation with smooth 4-inch mandrel-bent stainless tubing and a free-flowing muffler core. This drops peak EGTs by up to 100–200°F, improves throttle response, and provides MBRP's deep "Street Profile" exhaust note without obnoxious highway in-cab drone. It is a complete 4-inch cat-back exhaust kit including the intermediate extension pipe, chambered muffler, over-axle pipe, tailpipe, 5-inch polished tip, and band clamps; turbo downpipes and catalytic converter delete pipes are sold separately.

It fits 2003–2007 Ford F-250 and F-350 Super Duty pickup trucks equipped with the 6.0L Powerstroke diesel engine across SuperCab (Extended Cab) and Crew Cab configurations with 6'9" Short Beds or 8' Long Beds that retain the factory catalytic converter (Regular Cab models require adapter pipe FS9449; does not fit Cab & Chassis models or Ford Excursions).

Fitment

• 2003–2007 Ford F-250 Super Duty 6.0L Powerstroke (SuperCab & Crew Cab; Short & Long Bed)
• 2003–2007 Ford F-350 Super Duty 6.0L Powerstroke (SuperCab & Crew Cab; Short & Long Bed)
• Fits Single Rear Wheel (SRW) and Dual Rear Wheel (DRW) pickup configurations
• Direct bolt-on cat-back installation behind the factory catalytic converter (50-state emissions legal)
• Smooth 4-inch mandrel-bent 16-gauge T409 stainless steel tubing for lasting corrosion resistance
• Spiral-louvered high-flow performance muffler lowers EGTs while providing a moderate, drone-free tone
• Includes premium 5-inch OD angle-cut mirror-polished T304 stainless steel exhaust tip
• OE-style welded hangers mount directly into factory rubber chassis isolators
• Backed by MBRP’s Lifetime Warranty
• Complete cat-back exhaust kit including heavy-duty band clamps and installation hardware

Support the vehicle securely on a heavy-duty lift or tall jack stands and disconnect both negative battery cables. Spray penetrating lubricant onto the factory two-bolt exhaust flange nuts behind the catalytic converter and all factory rubber hanger isolators along the frame rail. Unbolt the factory flange directly behind the catalytic converter using an impact wrench or heat if the studs are rusted. Slide the factory exhaust rearward to disengage the hangers from the rubber chassis mounts and lower the original intermediate pipe, muffler, and tailpipe assembly out from under the truck (cutting the over-axle pipe with a reciprocating saw eases removal if working on jack stands). Measure and trim the provided intermediate pipe according to the cab and bed length specifications in the instructions, then bolt the adapter loosely to the catalytic converter outlet flange. Slide the performance muffler onto the intermediate pipe, supporting it with a stand, and guide the over-axle and tailpipe sections over the rear axle housing, slipping the welded hangers into the OEM rubber mounts. Install the 5-inch polished T304 stainless tip onto the tailpipe exit behind the passenger rear tire, align all pipe sections to ensure a minimum of 1 inch of clearance around brake lines, rear shock absorbers, fuel tank shielding, and the spare tire, then torque all heavy-duty band clamps progressively from front to back to 35–40 ft-lbs.