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Duramax Buyer's Guides

Guide

Best Duramax Exhaust Systems: DPF-Back, Cat-Back & Downpipes

How to choose an exhaust for your GM Duramax — DPF-back vs. cat-back vs. turbo-back, 4-inch vs. 5-inch diameter, aluminized vs. 409 vs. 304 stainless, the manifold and up-pipe leaks no kit fixes, and why freer flow drops EGTs on the LB7, LLY, LBZ, LMM, LML, LGH, and L5P.

August 3, 2026

Guide

Best Duramax Turbo Upgrades: Stock Replacements to Compounds

How to choose a turbo for your GM Duramax — which turbo came on your engine, how to fix a sticking VGT, and when to step up to a drop-in upgrade or compounds on the LB7, LLY, LBZ, LMM, LML, and L5P.

July 22, 2026

Guide

Common Duramax Problems by Generation (and the Parts That Fix Them)

A straight-talk reference to the known weak points of every 6.6L Duramax — LB7 injectors, LLY overheating, LBZ/LMM sticking turbo vanes, LML CP4 failure, L5P — and the exact parts that fix each one.

July 26, 2026

Guide

Duramax CP3 vs. CP4 Fuel Pump Guide: Which Pump You Have & Why It Matters

Which GM 6.6L Duramax has the Bosch CP3 and which has the CP4.2 — why the CP4 fails catastrophically, how a CP3 conversion or disaster-prevention kit protects your LML, and the fuel filtration that keeps either pump alive.

July 29, 2026

Guide

Duramax EGR & Cooling Guide: Coolers, Radiators & Fixes

Diagnose and fix Duramax cooling and EGR failures — what fails on the LB7 through L5P, the codes that point to an EGR cooler, how to tell coolant loss from a head gasket, and what to compare when you buy a replacement cooler, radiator, water pump, or thermostat.

July 22, 2026

Guide

Duramax Generations & Fitment Guide: LB7 to L5P by Year

A year-by-year reference for every GM Duramax generation — LB7, LLY, LBZ, LMM, LML, LGH, and L5P — mapped to the GMT800, GMT900, K2XX, and T1XX truck platforms, so you order parts that actually fit your Chevy Silverado or GMC Sierra HD.

July 23, 2026

Guide

Duramax Glow Plug & Cold-Start Guide: Hard Starts, Codes & the Parts That Fix Them

Why your 6.6L Duramax won't start when it's cold — how the glow plugs and controller work, which plugs each generation (LB7→L5P) uses, and how to tell whether it's the plugs, the GPCM controller, weak batteries, or air in the fuel.

July 30, 2026

Guide

Duramax Head Gasket & Head Stud Guide: Why Heads Lift & How to Fix It

Why the GM 6.6L Duramax lifts head gaskets under boost, how to read the symptoms, and how ARP head studs vs. factory torque-to-yield bolts change the fix — by generation, from the LB7 to the L5P.

August 2, 2026

Guide

Duramax Injector Buyer's Guide: LB7 to L5P Symptoms, Types & Replacement

How to choose fuel injectors for your GM 6.6L Duramax — reading failure symptoms, understanding stock vs. reman vs. performance injectors, the LB7 vs. common-rail differences, and the return-line 'black death' fix by generation.

July 27, 2026

Guide

Duramax Maintenance Schedule & Parts Checklist (6.6L Service Intervals)

A mileage-by-mileage service schedule for the 6.6L Duramax — oil, fuel filters, air filter, glow plugs, coolant, transmission, and the wear parts to keep on the shelf. Intervals and part types for LB7 through L5P.

July 25, 2026

Guide

Duramax Tuner & Programmer Buyer's Guide: Tunes, Monitors & Doing It Right

How to choose a tuner or programmer for your GM 6.6L Duramax — what a tune actually changes, EFILive vs. handheld vs. cloud tuners, transmission and towing tunes, gauges and monitoring, and the supporting hardware a tune commands. Legal, off-road, and emissions framing explained.

July 31, 2026

Guide

Duramax VIN & Engine Code Decoder: Every 6.6L by Year (LB7–L5P)

Decode your Duramax from the VIN. The 8th-digit engine code for every 6.6L generation — LB7, LLY, LBZ, LMM, LML, LGH, L5P — plus the 10th-digit model-year chart and the RPO sticker, so you order parts for the engine you actually own.

August 5, 2026

Guide

LB7 vs L5P Duramax: Which Generation to Buy and How to Build It

A full head-to-head of the LB7, LLY, LBZ, LMM, LML, LGH, and L5P Duramax — power ratings, injection pumps, emissions hardware, transmissions, the weak point of each engine, and the first part every generation actually needs.

July 22, 2026

Guide

LBZ vs L5P Duramax: Which Generation Should You Buy or Build?

The LBZ (2006–2007) and L5P (2017+) are the two most-loved Duramax generations for opposite reasons. Compare reliability, tuning, power, emissions, and the first parts each one needs — so you buy and build the right truck.

August 1, 2026