The Mini Maxx was a touchscreen tuner made by H&S Performance that let diesel owners add power and remove emissions equipment. The EPA shut the company down in 2013 with a massive fine, and the device has not been legally manufactured or sold since.
- The Mini Maxx was a dash mounted touchscreen tuner for Cummins, Powerstroke and Duramax trucks
- Its main selling point was tunes that removed the DPF, EGR and DEF systems
- H&S Performance was shut down by the EPA in 2013 and fined tens of millions of dollars
- No new units exist. Everything for sale today is used, unsupported and legally risky
If you owned a diesel truck between 2008 and 2013, you knew the name Mini Maxx. It was everywhere. Forums, shops, truck meets. A little touchscreen on the dash that promised more power and better mileage with a few taps. At its peak, it was the best selling diesel tuner in North America.
Then the company behind it got shut down by the federal government, and the Mini Maxx became a piece of diesel history. Here is the full story, and what it means if you still have one.
What the Mini Maxx actually was
The Mini Maxx was a dash mounted performance tuner made by H&S Performance, a company based in Utah. It plugged into the OBD II port and did two things. First, it worked as a digital gauge display, showing boost, exhaust gas temperature, rail pressure and dozens of other readings on a full color touchscreen. That part was genuinely useful. Plenty of owners bought it just for the gauges.
Second, and this was the real selling point, it loaded performance tunes into the engine computer. The tunes added serious power, often 100 horsepower or more on a Cummins. But the tunes that made the Mini Maxx famous were the ones that turned off the emissions systems. Load the right tune and the truck stopped looking for its DPF, stopped recirculating exhaust gas through the EGR and stopped injecting DEF. That is what "delete tunes" meant, and that is why everyone wanted one.
Why the EPA shut it down
Here is the part the old forum posts skipped. Selling a device whose purpose is to defeat emissions controls on road vehicles violates the Clean Air Act. The EPA does not treat that as a gray area.
In 2013 the EPA and the Department of Justice came down on H&S Performance. The company agreed to stop making and selling defeat devices and paid a massive civil penalty reported in the tens of millions of dollars. It was one of the largest emissions enforcement actions against an aftermarket company at the time. H&S Performance never recovered. The Mini Maxx died with the company.
This was not a one off. The EPA has gone after one delete tuner company after another ever since, with fines reaching into the millions each time. The message has been consistent for over a decade. If your product exists to defeat emissions equipment, the government will eventually find you.
What happened to the trucks
When H&S shut down, support ended overnight. No more firmware updates. No more new tunes. No customer service line. Owners were left with a device frozen in time, running software from 2013 on trucks that kept aging.
That is the situation still in place today. Every Mini Maxx in existence is at least a decade old. The touchscreens are failing. The internal batteries are dead. And the tunes on them were written for trucks as they existed years ago.
The used market is a trap
Search online and you will still find Mini Maxx units for sale. Here is what the sellers do not tell you.
Most used units are VIN locked to the truck they were last installed on. Unlocking one requires an unlock code, and with the company gone, getting a legitimate code is somewhere between difficult and impossible. An locked tuner is a paperweight.
Even if you find an unlocked one, you are buying a decade old electronic device with no support, no updates and a failing screen supply. And the tunes it carries are emissions defeat tunes. Installing one on your truck and driving it on public roads is illegal in both Canada and the United States, with fines that dwarf whatever you paid for the tuner.
What to do if you have one
If there is a Mini Maxx on your dash right now, here is my honest advice as a mechanic.
If the truck still has its emissions equipment intact and the tuner is just being used for gauges, you can keep using the gauges. But have a plan for when the screen dies, because it will.
If the truck was deleted with Mini Maxx tunes, understand what you own. The truck is not emissions compliant. That affects resale, trade in value and your legal exposure. Plenty of owners in this spot choose to return the truck to stock with the help of a reputable shop. It costs money, but it makes the truck sellable and legal again.
Read our guide on what a DPF delete really means for the full picture on the legal side. The Mini Maxx story is the clearest example in diesel history of why the delete era ended the way it did.
Frequently asked questions
Can I still buy a new Mini Maxx tuner?
No. H&S Performance was shut down by the EPA in 2013 and the Mini Maxx has not been manufactured since. Anything advertised as new is either old stock from before the shutdown or a counterfeit. Neither comes with support or updates.
Should I buy a used Mini Maxx?
I would not. Used units are often locked to the previous truck, screens are failing from age, and there is no company left to help you. More importantly, the tunes it runs are emissions defeat tunes, which are illegal on any truck driven on public roads in Canada and the United States.
Is my truck illegal if a previous owner installed a Mini Maxx?
If the emissions equipment was removed, yes, the truck is not compliant for road use no matter who did the work. Many buyers discover this at trade in time when a dealer refuses the truck. Talk to a reputable diesel shop about your options before you get surprised.