Duramax Tuning

Custom EFI Live Tuning · Duramax

Every Duramax.
Every generation.
Tuned right.

Custom EFI Live tunes for LB7, LLY, LBZ, LMM, LML, and L5P. Up to five tune positions switchable on the fly via CSP5. Hand-built for your truck, your mods, your goals.

Shop Duramax Tunes How it works
⚙
All Duramax Generations
⬢
CSP5 Multi-Position Tuning
★
Allison Trans Tuning
▲
Lifetime Tune Support
01 · The Process

Custom Duramax tuning,
three steps.

We tune every Duramax generation differently. The LB7 is not the L5P. Generic doesn't work — and we don't sell it.

01

Pick your platform

LB7, LLY, LBZ, LMM, LML, or L5P. Each generation gets a tune family built for its specific characteristics. Tell us your mods and goals.

02

We build your tunes

Multiple positions on a single AutoCal or CSP5: tow, daily, hot, hot-er. Switch between them with the press of a button without leaving the truck.

03

Flash and drive

Tunes load to your AutoCal or via direct flash. Lifetime revisions — when your build changes, we re-tune for free. Always.

02 · What's Included

Every Duramax tune package
comes loaded.

✓
Up to 5 tune positions Multi-position tuning via CSP5 switch. Twist the knob, change the tune.
✓
EFI Live AutoCal compatibility Industry-standard hardware. Add it to your order or use what you already own.
✓
Mod-specific calibration Tuned for your turbo, injectors, fuel system, lift pump, exhaust.
✓
Allison 1000 trans tuning Locked converter, firmer shifts, raised line pressure. Keeps the trans alive.
✓
Lifetime tune revisions Build changes? We can re-tune. For as long as you own the truck.
✓
Direct specialist support Real Duramax guys, seven days a week. We run these trucks ourselves.
50K+
Trucks Tuned Since '10
98%
Positive Customer Reviews
4hr
Average Tune Delivery
7d
Support Availability
03 · Tune Packages

Pick your Duramax.

Tune packages built for the three most common Duramax platforms. Each is fully customized to your mods and goals.

LB7 / LLY · 2001-2005

Early Duramax Tune Pack

Custom EFI Live tunes for the early LB7 and LLY Duramax. Multi-position tuning with optional Allison 1000 transmission tuning.

$400
View tune
LBZ / LMM · 2006-2010

LBZ & LMM Tune Pack

The fan-favorite LBZ and the LMM. CSP5 multi-position tuning, calibrated to your build. Trans tuning available.

$400
View tune
LML / L5P · 2011-Current

Modern Duramax Tune Pack

Modern Duramax tuning for LML and L5P. Tow, daily, and performance positions. Allison trans tuning included.

$400
View tune
04 · From Real Customers

What Duramax owners
say about us.

★★★★★

"CSP5 with five positions is a game changer. Stock for the dealer, tow for the trailer, daily for around town, hot for fun, and a built tune for when I really need it. Worth every penny."

Brandon T.
2007 GMC 2500HD · LBZ
★★★★★

"I'd been running canned tunes for years and thought that was as good as it got. Custom from Stealth is on a different level. Smoother, faster, better MPG. These guys know Duramax."

Eric M.
2014 Chevy 3500 · LML
★★★★★

"Allison trans tune was the missing piece. Truck shifts firm, holds gears, doesn't hunt. Engine tune is dialed. Lifetime support is real — added an S475 and they had the new tune to me in two days."

Kyle B.
2019 Chevy 2500HD · L5P
05 · Frequently Asked

Questions answered.

For most Duramax owners, EFI Live with the AutoCal or CSP5 is the industry standard — it gives you multi-position tuning with on-the-fly switching via a physical knob. EZ Lynk is also supported on newer Duramax trucks via cloud delivery and phone-based switching. We'll recommend the right platform based on your truck and how you want to use the tunes.
(SOTF)DSP5 is a 5-position rotary switch that lets you change between tune positions (e.g., stock, tow, daily, hot, hot-er) without using a laptop or phone. It mounts in-cab. Once installed, switching tunes is a literal twist of a knob.
Yes. Allison 1000 transmission tuning is available and recommended any time you increase engine power. A locked converter and adjusted shift firmness keeps the trans alive when the engine starts making real power.
Yes, we tune every Duramax generation from LB7 (2001-2004) through L5P (2017+). Each generation has its own characteristics and we have tune libraries built for each. The LB7 actually responds beautifully to a proper custom tune.
A properly built tune should not throw codes during normal operation. If you're seeing CEL after tuning, contact us — that's what lifetime support is for. We'll diagnose and fix.
With DSP5 or SOTF, up to 5 positions on a single device. Typical setup is stock / tow / daily / performance / extreme — but you tell us how you use the truck and we'll recommend the right mix.
Same day for the tune files. If you're ordering hardware (AutoCal, DSP5), shipping is fast and free over $100. Most customers are flashing within a week of ordering.
That's where custom tuning shines. Generic tunes can't account for big turbos, race fuel systems, ported heads, or aggressive cams. We've built tunes for everything from mild dailies to serious competition trucks. Send us your build sheet and we'll do the rest.

Run the Duramax
it should be.

Order online, get your custom tunes quickly, and feel the difference the first time you twist the DSP5 knob.

Shop Duramax Tunes