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TruckTok 2015.5-2016 6.6L GM Duramax LML 4" Downpipe Back DPF Delete Pipe
Brand TruckTok

TruckTok 2015.5-2016 6.6L GM Duramax LML 4" Downpipe Back DPF Delete Pipe

SKU DP-0300
$649.00 - $649.00
$649.00
$649.00 - $649.00
$649.00

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Availability:
in stock, ready to be shipped

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FITMENT

  • 2015.5-2016 6.6L Silverado & Sierra Duramax 2500HD/3500HD LML engine models with the 3-bolt flange.
  • Does NOT Fit 2011-2015.5 model with the V-Band Clamp style. 
  • Please physically inspect underneath your truck to verify your turbo discharge style before purchasing!

DESCRIPTION

Product Overview

  • Late-production 2015.5-2016 LML trucks have hit their peak emissions failure window. Soot-choked DPFs, blown DEF heaters, and failed sensors frequently trigger Limp Mode while tanking fuel economy to 13-14 MPG.
  • Furthermore, towing with these restrictions traps intense backpressure, spiking EGTs past 1,300°F and straining the turbo. At this age, mid-section patch pipes aren't enough, as the stock 10-year-old tailpipes and hangers are often heavily rusted and ready to snap.

Key Features

  • Rugged T-409 Stainless Steel Build: Manufactured from industrial-grade T-409 SS, perfectly optimized to expand and contract under intense thermal cycling without cracking or warping.
  • Continuous 4" Mandrel-Bent Tubing: Engineered with smooth, 4" diameter paths featuring zero internal neck-downs or restrictive bungs, providing the ultimate sweet spot for exhaust gas velocity.
  • Substantial EGT & Heat Reduction: Instantly drops exhaust backpressure, allowing scorching gases to exit the motor rapidly, dropping EGTs significantly under heavy sustained towing loads.
  • Precision 3-Bolt Flange Receiver: Equipped with a heavy-duty, CNC machine-cut 3-bolt flange welded at the inlet, guaranteeing a direct, leak-free bolt-on connection to your 15.5-16 factory downpipe output.

FAQ

Q: How loud is this full straight-pipe system? Will it drone inside the cab?

A: This Full straight pipe delivers a crisp tone and turbo whistle but causes highway cabin drone. For daily commuting or family towing, we highly recommend adding 4" Muffler. It tames harsh drone and raspy frequencies perfectly while preserving a deep, muscular diesel V8 rumble.

Q: Will this stop my truck's DEF system from throwing codes and failing?

A: Yes. Once you flash a delete tune and install this pipe, the entire DEF/SCR system is deactivated in the software. The DEF fluid injector stops spraying, the failure-prone tank heater stops cycling, and the NOx sensors are turned off. You will say goodbye to DEF-related check engine lights and countdown timers forever.

Q: How much horsepower will the 5" system add over this 4" version?

A: Zero, unless heavily modified. On a stock turbo, both systems make identical horsepower, but the 4" version preserves sharper low-end throttle response. Choose the 5" pipe only if your LML features a built transmission and aftermarket turbo to handle maximum high-RPM airflow.

Q: Can I install this 4" downpipe-back system myself in my garage?

A: Yes. The system is a direct bolt-on replacement that slips perfectly into your truck's factory rubber mounts. It takes about 1 to 2 hours in a driveway using basic hand tools and jack stands. We highly recommend soaking the old factory bolts in penetrating oil a few hours before starting.

  • 5 stars: 4 (44%)
  • 4 stars: 3 (33%)
  • 3 stars: 2 (22%)
  • 2 stars: 0 (0%)
  • 1 star: 0 (0%)
This product has no reviews of its own. The merchant grouped it with related products, so the reviews shown are from across that group.
H
Hank Boudreaux
You need the 3-hole downpipe flange — this kit has it

2015.5 LML uses a 3-hole turbo flange, not the 4-hole from 2011-2014. I learned this the hard way with another brand's kit. The TruckTok system includes the correct 3-hole downpipe and it bolted right up. The gasket is multi-layer steel, not a paper one that blows out. The 5-inch downpipe has a smooth mandrel bend from the turbo flange all the way back. No neck-downs anywhere in the system.

C
Charles Lawless (United States)
Great product

Great quality

B
Beau Stockton
Save your factory exhaust — you might need it down the road

Took me about 4 hours solo. The hardest part was removing the factory DPF assembly intact. If you are in an emissions-testing state like me, you want to keep the factory exhaust in one piece. I was able to remove it without cutting anything by dropping the transmission crossmember for clearance. The TruckTok 5-inch pipe went in clean — all slip joints fit tight and the band clamps pulled everything solid.

J
Jordan Cress (United States)
5” exhaust

Fit like a glove, good quality clamps

C
Colt Mabrey
Late LML DPF is the worst one GM made — delete it

2015.5 Silverado 2500. I have owned an LB7, an LBZ, and now this LML. The LML DPF is by far the most problematic. It regens constantly, it cracks internally, and the DPF differential pressure sensor fails regularly. This TruckTok 5-inch system permanently removes all of that. The engine runs like a Duramax should — smooth, responsive, and cool. The 5-inch pipe makes a real difference in sound quality over the 4-inch kits. 30K miles on it, zero issues.

C
Colt Prather
2016 LML — zero fitment issues on the last year

My 2016 Denali HD was the last year of the LML body. The exhaust routing on the 2015.5-2016 is slightly different from 2011-2014 because of the CP4.2 pump clearance. This TruckTok system is clearly designed for these years — the downpipe clears the transmission and the 5-inch pipe routes around the spare tire without rubbing. All factory hangers fit and the polished tip exits at the stock location. Took a Saturday with basic tools.

R
Rusty Weatherby
2015.5 LML — 5-inch over 4-inch is worth the upgrade

2016 Silverado 3500. The late LML (2015.5-2016) has the CP4.2 pump and the factory DPF chokes the engine just as bad as the earlier trucks. Went with the TruckTok 5-inch downpipe-back system instead of a 4-inch and I am glad I did. EGTs under load dropped 180 degrees compared to my buddy's 4-inch delete on the same truck. The 5-inch pipe moves more air and the tone is deeper. If you tow heavy, skip 4-inch and go straight to 5.

D
Dusty Fontenot
15 to 20 mpg — and the CP4 finally gets clean oil

2015.5 Silverado 2500. The factory DPF regen cycle was dumping fuel into the cylinders and my oil was black by 2500 miles. On a CP4.2 truck that is a recipe for disaster. Deleted with this TruckTok 5-inch system and a tune. Oil now stays clean past 7000 miles. Fuel economy went from 15 to 20 on the highway. The 5-inch pipe gives it a deep growl at idle without being obnoxious on the highway.

W
Waylon Hightower
The 5-inch tip looks aggressive on the LML bumper

The late LML with the factory square exhaust tip cutout looks great with a 5-inch polished tip filling the hole. The TruckTok tip is double-walled with a rolled edge — it does not look like a thin-walled pipe jammed through the bumper. The 5-inch size fills the factory cutout perfectly with just enough clearance. No rattling against the bumper bracket. This is the visual upgrade the LML needs to match the delete performance.