Collection: 2017-2019 Duramax L5P

6.6L Duramax L5P — Tuning, EGR, Exhaust & Fuel

Calibrated tuning, EGR upgrade kits, exhaust, and fuel hardware for the 2017–2019 GM 6.6L Duramax L5P. The L5P uses a locked E41 ECM that requires an unlock service before it can be tuned; builds pair that with calibrated files, airflow, and supporting hardware. Every part here is matched to your truck and ordered the way you'd build it.

What you need to tune the 6.6L Duramax L5P

A supported device (EZ Lynk Auto Agent, HP Tuners MPVI4, MM3, GDP Commander) plus a Dieselr-calibrated tune file — GDP and Chaos Custom Tuning calibrations are also available. EZ Lynk requires no send-in.

Exhaust & off-road hardware

Downpipe-back and turbo-back exhaust in aluminized and stainless, plus Cat & DPF race pipes for off-road and competition use. Larger-diameter exhaust lowers EGT and frees airflow as power climbs. EGR upgrade kits include block-off plates, coolant bypass, gaskets, and EGT provision. Off-road and competition use only; pair with a matching calibration so the engine runs correctly.

Fuel

FASS, S&S Diesel, Dynomite Diesel, and Dieselr fuel hardware support higher fueling as power climbs.

Compatibility

Organized by confirmed fitment for the 2017–2019 GM 6.6L Duramax L5P.

FAQ

What do I need to tune a 6.6L Duramax L5P?
A supported device plus a Dieselr-calibrated tune file. Add off-road EGR and exhaust hardware if your build moves past the factory emissions configuration.

Do I need a tune with an EGR upgrade kit?
Yes — the calibration prevents fault codes and derate after the hardware change.

Why does the L5P need an unlock service?
The L5P's E41 ECM is locked from the factory; an unlock service is required before it can be tuned.

What fuel upgrade do I need?
Stock-to-mild builds run the factory system; higher power calls for added fuel supply and supporting hardware.

Are EGR upgrade kits and race pipes street legal?
These products are intended for off-road and competition use only. It is the buyer's responsibility to comply with all applicable federal, state, provincial, and local emissions laws.