5″ GM Duramax 6.6L LML 2015.5-2016 Exhaust Pipe

Here’s the detailed technical breakdown for the 5″ LML Duramax Exhaust (2015.5-2016) with critical installation and compliance information:

Key Identification & Fitment

⚠️ 2015.5-2016 LML Specifics

• Turbo Connection: 3-bolt triangular flange (vs. V-band on 2011-early 2015)

• Visual Confirmation Required:

  • Early 2015: clamp (circular)

  • Late 2015.5-2016: 3-bolt triangle (this kit)

System Specifications

Performance Data (With Tune)

• Backpressure Reduction: 4-6 psi

• EGT Drop: 175-225°F under load

• Turbo Response: 250-300 RPM faster spool

• Sound Profile: 8-12dB louder than stock (measured at 65 mph)

Installation Protocol

🔧 Critical Tools:

• 15mm deep socket (flange bolts)

• Torque wrench (38 lb-ft for flange)

• Exhaust hanger removal tool

⚠️ Must-Do Steps:

1. Disconnect negative battery terminal (prevents ECM errors)

2. Salvage sensors:

   • Exhaust backpressure (EBP) sensor

   • DPF pressure sensors (leave plugged in)

3. Apply copper anti-seize to flange bolts

Tuning Requirements

🚨 Immediate Tuning Mandatory – Otherwise:

• Limp mode in 30-50 miles

• P2463/P2459 codes (DPF-related)

• Continued regen attempts

Recommended Tunes:

• EFI Live (w/ DSP5 switch) – For multi-mode tuning

• MM3 LML Suite – Optimized DPF/DEF delete

• PPEI Tow-X – Best for heavy hauling

Legal Consequences

Required Supporting Mods

1. EGR Delete Kit (Prevents intake clogging)

2. 5″ Muffler Add-on (For drone reduction – PN: MBRP M5050AL)

3. Banks iDash (Monitor EGT/Boost/Regen attempts)

Street-Legal Alternative

For compliant vehicles:

• Flo~Pro 59452 – CARB-approved 4″ system

• GMPP-19354370 – GM’s factory performance exhaust