Kory Willis: The Tuner Who Changed Diesel Forever

The Man Who Wouldn’t Sit Still

In every industry, there are names that stick. They’re the ones whispered about in forums, chatted about at trackside, and debated over shop benches long after the wrenches were put away. In the diesel world, one of those names is Kory Willis.

To some, he’s a pioneer—the man who pushed tuning into places most never dreamed it could go. To others, he’s a symbol of what happens when innovation runs headlong into the cold wall of regulation. Either way, it’s impossible to tell the story of modern diesel performance without telling the story of Kory Willis.

Kory Willis grew up with an instinct for horsepower. Tinkering with machines wasn’t just a pastime; it was a calling. In 2008, he turned that passion into a business—Power Performance Enterprises, Inc. (PPEI), based in Louisiana. What began as a small tuning outfit quickly grew into one of the most influential shops in the country.

With platforms like EFILive and EZ-Lynk, Kory carved out a reputation for precision and results. Duramax, Power Stroke, Cummins—it didn’t matter. If you wanted your truck to pull harder, run cleaner, or simply feel “the way it should have from the factory,” as Kory once put it, you called PPEI.

But let’s not sugarcoat it: Kory’s rise coincided with the peak of “delete culture.” The mid-2010s diesel world thrived on tunes that removed emissions systems. These delete tunes promised reliability, performance, and better fuel economy, and enthusiasts lined up in droves.

“We gave people what they wanted,” Kory said in a Facebook post later cited by TankTransport.com. And it was true. Diesel owners were tired of clogged filters and limp modes. They wanted their trucks unchained, and Kory gave it to them.

At PPEI, Kory became the name in deletes. His tunes were everywhere—on drag strips, sled pull tracks, and even daily drivers. For a time, it felt like he could do no wrong. But Washington wasn’t watching with admiration. It was watching with a clipboard in hand.

In March 2022, the hammer dropped. The Department of Justice and the EPA charged PPEI and Willis with violating the Clean Air Act, alleging that their delete tunes had resulted in more than 100 million pounds of excess nitrogen oxide emissions between 2013 and 2018..

The penalty was staggering—more than $3.1 million in combined criminal fines and civil penalties. PPEI was also placed under probationary restrictions. Willis himself was sentenced to three years of probation, including ten months of home confinement.

“These unlawful actions resulted in more than 100 million pounds of excess pollution,” the EPA stated flatly. The agency framed PPEI not as an innovator, but as an environmental offender.

For Kory, it was the hardest chapter yet. But he didn’t disappear. He recalibrated.

After the lawsuit, PPEI was forced to pivot or die. Gone were the delete tunes. Gone was the language about “off-road only.” Instead, PPEI repositioned itself around emissions-intact, compliance-based tuning. Its new goal was clear—prove that you could still deliver performance without crossing the line.

“The industry is evolving, and so am I,” Kory said in a PPEI press statement. “My goal now is to prove performance and compliance can live together.”

That pivot wasn’t just talk, though. PPEI began working toward CARB certification—the gold standard for emissions legality in strict states like California. Their marketing shifted to emphasize towing, drivability, and fuel efficiency. It was a new PPEI—one built to survive the new era of emissions enforcement.

But if you thought Kory would sit quietly in a corner, you don’t know him very well. While PPEI adjusted, Willis himself leaned harder into motorsports. He became a driver in Nitrocross, piloting UTVs and off-road rigs, keeping his name in headlines for reasons that had nothing to do with lawsuits.

His Instagram, @kory_ppei, still buzzes with builds, racing highlights, and behind-the-scenes glimpses of a man who refuses to quit. Whatever else you can say about him, Kory doesn’t know how to stop moving.

So what do we make of Kory Willis? Villain? Visionary? The truth is more complicated.

Yes, he pushed deletes hard in an era when the diesel world was hungry for them, and yes, the legal fallout was massive. But to reduce him to just that would be to ignore the larger arc. He helped define what diesel tuning could be. He raised the standard for what customers expected from a tune. And now, in a twist no one predicted, he may also help define what compliant tuning looks like.

Love him or hate him, Kory Willis is still here. His company is still tuning trucks. He’s still racing. The diesel community is still watching, and Kory is still advocating for diesel truck owners everywhere.

Pioneers often pay the steepest price, but they also open doors others would never have found. Kory Willis is one of those pioneers. And as the diesel industry keeps shifting toward emissions compliance, it’s hard not to wonder: will the man once vilified as the king of deletes end up being remembered as one of the architects of legal diesel performance?

If history is any guide, Kory won’t stop chasing that possibility. And we’ll still be talking about him years from now.