aFe Large Bore-HD 4in 409SS DPF-Back Exhaust, Black Tips - 2020-2026 GM 6.6L L5P Duramax 2500/3500 HD

aFe Large Bore-HD DPF-back exhaust system for the 2020-2026 GM 6.6L L5P Duramax, converting the factory single outlet into an aggressive dual setup. Built from 4" mandrel-bent 409 stainless steel tubing and finished with dual 5" black 304 stainless steel intercooled clamp-on tips carrying a riveted aFe POWER logo plate. A mitered merge collector reduces turbulence and increases exhaust velocity for added horsepower, torque and throttle response. The system is 100% MIG-welded and mounts to factory hanger locations using the included hardware; some cutting may be required per the instruction sheet. This is a Non-CARB (49-state) part, not legal for sale or use in California.

Specifications

This part fits:

Shipping

• In-stock orders placed before 3 PM EST ship the same day — everything else ships within 24 hours.
• Standard, expedited, and overnight options at checkout.
• Oversized items ship by freight and take longer.
• Backordered items ship as soon as stock lands — contact us for lead times.
• International orders: prices do not include VAT, duties, or import fees. Your country charges these at import and they are the buyer’s responsibility.

Returns

• 30-day returns on new, uninstalled items in original packaging with all hardware.
• Standard returns: 8% restocking fee, buyer pays return shipping. Both waived if the item is defective or we made the error.
• Installed or used parts can’t be returned — confirm fitment before you install.
• Special orders and custom items are final sale.
• Email us for return authorization before shipping anything back.

Full details: Shipping Policy · Refund Policy