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TruckTok 2015.5-2016 6.6L LML Duramax Diese 3 inch Downpipe Exhaust
Brand TruckTok

TruckTok 2015.5-2016 6.6L LML Duramax Diese 3 inch Downpipe Exhaust

SKU DP-0038
$139.49 - $139.49
$139.49
$139.49 - $139.49
$139.49

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Availability:
in stock, ready to be shipped
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FITMENT

  • 2015.5-2016 6.6L Silverado & Sierra Duramax LML 2500HD/3500HD Diesel engine pickup.
  • This downpipe features a 3-Bolt Flange connection at the turbo outlet. 
  • NOT fit 2011-2015.5 models that utilize the V-band style clamp connection.

DESCRIPTION

Product Overview

  • The factory downpipe on Duramax LML trucks is a major performance bottleneck. To squeeze past tight engine bay clearances, GM engineers severely crushed and flattened the stock pipe.
  • This restricted "pancake" design chokes exhaust flow, traps excessive thermal energy right at the turbo charger, and spikes EGTs under heavy towing loads.
  • Upgrading to smooth, 3" mandrel-bent downpipe maximizes exhaust flow right from the turbo outlet, rapidly dropping EGTs and allowing the turbo to spool up much faster.

Key Features

  • Premium T-304 Stainless: Computerized Mandrel-Bends and heavy-duty 16-gauge T-304 SS ensure maximum rust-resistance and structural strength.
  • TIG-Welded Construction: All joints are precision TIG welded and jig-built to prevent cracking under high thermal cycling and aggressive vibration.
  • Unrestricted 3-Inch Bore: Replaces the restrictive, "crushed" factory oval pipe with a true, consistent 3-inch mandrel-bent round diameter through every turn.
  • Drastic EGT Reduction: Smooths out exhaust flow to quickly draw extreme heat away from the turbo, reducing under-hood temperatures and protecting engine longevity.

FAQ

Q: What are the main benefits of upgrading the late-LML downpipe?

A: The factory downpipe is severely crushed into a flat shape to clear the firewall. Replacing it with our true 3" round mandrel-bent pipe lowers backpressure and EGTs significantly, eliminating turbo lag while freeing up a deep diesel exhaust note.

Q: How do I tell if my truck needs the V-band or 3-bolt version?

A: Look at the turbo outlet. 11-15.5 trucks have a V-band clamp (hose clamp style, no bolts). 15.5-16 trucks have a 3-bolt flange (three bolts in a triangular pattern). Purchase as needed: 11-16 LML DPF/EGR Delete Kit.

Q: Does this downpipe require custom tuning?

A: If installed on a stock truck with all 2 factory sensors reinstalled correctly, no custom tuning is required and it will not trigger a Check Engine Light. If you choose to delete the sensors, an emission-delete tune is required.

Q: What exhaust should I pair with this downpipe to maximize performance?

A: Pair this downpipe wit LML DPF Delete Pipe or DP-Back Exhaust. While this pipe frees up the turbo outlet, the delete pipe eliminates the restrictive factory DPF/CAT downstream. Together, they create a fully unrestricted system that maximizes flow, slashes EGTs, and delivers a deep rumble with zero cabin drone.

  • 5 stars: 4 (80%)
  • 4 stars: 1 (20%)
  • 3 stars: 0 (0%)
  • 2 stars: 0 (0%)
  • 1 star: 0 (0%)
H
Hank Stockton
2016 LML — zero fitment issues

Two bolts at the turbo and a hanger at the transmission. That is all that holds the LML downpipe. This one bolted in without any prying or grinding. The turbo flange surface was machined flat and the gasket sealed first try. The pipe routes exactly like factory but without the crushed bend and the necked-down section. 12,000 miles on it and no leaks, no rattles, no issues. This is the pipe the LML should have had from the factory.

B
Beau Hightower
Great pipe — my factory V-band was toast

The downpipe itself is excellent — 304 stainless, thick flange, smooth bends. The only hassle was my factory turbo V-band clamp was rusted solid on a 2016 with 90K miles. Had to cut it off and buy a new one. Not the pipe's fault but budget $35 for a replacement clamp if your truck has seen salt. Install took an hour once I had the new clamp in hand.

W
Waylon Prather
Quick response — not a 200 RPM wait anymore

2015.5 Silverado 3500. The LML is known for turbo lag off idle. This 3-inch downpipe combined with a tune cut the lag noticeably. The turbo starts building boost about 250 RPM sooner according to my Edge monitor. From a dead stop with a trailer the truck just goes instead of hesitating. For the price this is one of the best bang-for-buck mods on the LML platform.

R
Rusty Fontenot
3-hole flange — finally a downpipe for late LML

2016 Silverado 2500. The 2015.5-2016 LML uses a 3-hole turbo flange instead of the 4-hole from 2011-2015. Bought an earlier LML downpipe by mistake and it didn't fit. This TruckTok pipe has the correct 3-hole pattern and bolted right up. The mandrel bend clears the firewall and the transmission bellhousing with room to spare. If you have a late 2015 or 2016, this is the one.

C
Colt Boudreaux
Made the factory DPF delete pipe sound right

2015 GMC Denali HD. I did the DPF delete first but kept the factory downpipe. The sound was weird — muffled and uneven. Adding this 3-inch downpipe made the exhaust sound correct — deep and consistent idle, clean turbo spool sound. The factory downpipe has internal baffling and a pinched bend that kills flow and sound. This pipe is smooth inside and out. The truck now sounds like a diesel should.