Seguler 2004.5-2005 6.6L Duramax LLY 5" DP-Back DPF Race Pipe & EGR cooler Delete Kit

FITMENT

• 2004.5-2005 6.6L Chevrolet Silverado Duramax LLY 2500HD / 3500 HD.
  
• 2004.5-2005 6.6L GMC Sierra Duramax LLY 2500HD / 3500HD.

DESCRIPTION

Product Overview

• Heavy exhaust backpressure, choked intake geometry, and sticky carbon sludge severely limit the turbo spool and thermal efficiency of 2004.5–2005 LLY Duramax trucks.
  
• Uncork your engine’s breathing path with this 5" DP-Back Master Package. Designed to bypass restrictive exhaust components and prevent soot and oil mist from entering the intake, it accelerates boost response, drops towing EGTs, and ensures maximum charge-air delivery.
  

Key Features

• Replaces the restrictive OEM intake bridge with a high-flow 3" tube for an open path for cool, pressurized air.
  
• Unlocks noticeably faster spool and a crisper pedal by freeing airflow on both the intake and exhaust sides.
  
• Swaps the full factory exhaust from the downpipe back for smooth 5" pipe, maximizing velocity and dropping EGTs under heavy towing.
  
• Deletes the EGR and reroutes the CCV to keep oil and soot out of the intake, leaving it dry, clean, and carbon-free.

FAQ

Q: How is this 5" downpipe-back kit different from a standard race pipe? 

A: A standard race pipe only replaces the middle emissions canister. This 5" DP-back system replaces the entire exhaust from the turbo downpipe exit past the rear tire, removing every factory pinch point for maximum velocity.

Q: What does the 3" intake elbow add to this LLY kit? 

A: The factory LLY bridge is narrow and houses a restrictive throttle valve. A smooth 3" mandrel-bent elbow maximizes airflow into the manifold for faster boost and sharper throttle.

Q: Why does this kit include both the EGR delete and the CCV reroute? 

A: Stock LLY oil mist mixes with EGR soot like glue and powder, choking the intake with sludge. Deleting the EGR removes the soot and rerouting the CCV removes the oil, keeping the intake dry and clean.

Q: Is custom ECM tuning required after installation? 

A: Yes, it’s mandatory. Disabling the EGR and altering exhaust and intake pressure parameters will trip fault codes, so a custom delete tune is required to clear them and recalibrate fuel delivery.