RPM Northwest promotes a crew of elite technicians skilled at top-end upgrades that can enhance the performance of diesel trucks.

“Peace of Mind. You are in the hands of the industry’s finest,” declares the website for the business in Ridgefield, Clark County.

A 12-count federal criminal indictment made public Thursday alleges that the shop’s specialty work during the past three years included the illegal tampering of emission-monitoring systems on hundreds of diesel pickup trucks in violation of the federal Clean Air Act.

The indictment filed in U.S. District Court in Tacoma names as defendants Sean Coiteux and his wife Tracy Coiteux, as well as the two companies they control — RPM (Racing Performance Maintenance) Northwest and a related company nearby in Woodland, RPM Motors and Sales. It also charges Nick Akerill, the general and service manager of RPM Northwest, as a participant in the illegal activity.

The defendants are accused of modifying legally required software that controls pollution, and charged up to $2,000 per truck for the service. The indictment includes 11 counts resulting from work done on 11 trucks between January 2018 and November of last year, as well as a count alleging the work was part of a conspiracy that took in more than $500,000.

The work involves “defeat devices” that can increase power. Some of the demand has come from drag racers. Sometimes this work can enable a driver to perform a kind of exhaust-belch, known as “rolling coal,” which releases a black cloud of tailpipe emissions on targets of choice — including bicyclists and Prius drivers.


The modifications can increase pollution at rates of between 30 to 300 times that of trucks with the full suite of manufacturers controls in place, according to the indictment.

“These defendants increased toxins in our environment that are linked to cancer, as well as pulmonary, neurological, cardiovascular, and immune system damage. And they collected hundreds of thousands of dollars in fees for doing so,” said acting U.S. Attorney for Western Washington Tessa M. Gorman.

An attorney representing the defendants did not immediately respond to a request for comment Thursday afternoon. A representative at RPM Northwest said no one was available to comment.

EPA crackdown

The illegal meddling with pollution-monitoring systems gained notoriety in 2015 when the Environmental Protection Agency issued a notice of Clean Air Act violation to Volkswagen for software programming that resulted in much cleaner operations during emission testing than under normal road conditions.

In January 2017, the Justice Department announced that Volkswagen would pay a $2.8 billion criminal fine in a guilty plea, and $1.5 billion to settle civil environmental, customs and financial violations. The EPA also has given scrutiny to other devices to defeat pollution control systems on vehicles.

In a study published in November, the agency’s Office of Enforcement and Compliance, based on a review of enforcement efforts, found that pollution controls have been removed from more than 550,000 diesel pickup trucks during the last decade.


“The actual amount is unknown, but is higher than that,” said Evan Belser, deputy director of the EPA’s Air Enforcement Division, Office of Civil Enforcement.

Those vehicles represent about 15% of the diesel trucks in the U.S. originally outfitted with pollution controls. The trucks are estimated to have emitted more than 570,000 tons of additional oxides of nitrogen and 5,000 tons of particulate matter, which is the “air quality impact equivalent to adding more than 9 million additional (compliant, non-tampered) diesel pickup trucks to our roads,” the study states.

Diesel trucks, over the decades, have delivered more power even with pollution controls, according to Belser. But aftermarket modification still can result in “dramatic” gains in power, and that appears to be a big draw for those getting illegal work done.

Belser said that only some of the illegally tampered trucks are able to “roll coal.” These rigs may have dashboard-mounted control panels that allow operating parameters to be quickly changed to release this exhaust.

“We aren’t doing all this work just because of that behavior,” Belser said. “We’re doing this because there is a significant amount of excess pollution, most of which is invisible.”

The EPA has made these investigations a high priority and has pursued more than 70 civil enforcement cases.


Some of those cases have been in the Pacific Northwest. In March 2020, the EPA regional office in Seattle announced settlements with three manufacturers of aftermarket automotive parts — Deviant Race Parts and Alligator Diesel Performance, both-based in Hayden, Idaho, and owned by the same people, as well Diesel Power Products Unlimited of Spokane Valley.

The EPA alleged that these three companies collectively sold more than 70,000 products that thwart emissions control systems. The companies paid more than $180,000 in civil penalties to settle these cases, according to an EPA statement.

Then in March of this year, the EPA reached a $48,600 settlement with Adrenaline Performance of Shelley, Idaho, for allegedly selling and installing defeat devices.

The EPA enforcement actions have stirred a backlash as some accuse the agency of trying to cripple motorsports by stopping the conversion of street vehicles to dedicated race cars.

“Tell the bureaucrats in Washington that race cars are off-limits,” said an online post from the California-based Specialty Equipment Market Association, which bills itself as “Serving the Motor Vehicle Aftermarket,” and is seeking congressional legislation that “protect Americans’ right to convert street vehicles.“

RPM Northwest’s online advertising appears tailored to appeal to drivers who value speed, promoting Sean Coiteux, a defendant in the indictment made public Thursday, as a “storied MX racing legend” and “a snowmobile enthusiast (who will race you up the mountain whether you know you’re racing or not).”


The indictment against Sean Coiteux and other defendants, unlike most of the other EPA-investigated cases, is a criminal prosecution. A conviction on any one count of the Clean Air Act violations can result in prison sentences of up to two years. A conviction on the conspiracy count could result in up to a five-year sentence.

“As part of the Clean Air Act, Congress specifically made it a felony to tamper with emissions monitoring devices on diesel trucks,” said Seth Wilkinson, environmental crimes coordinator for the U.S. Attorney’s Office, Western District of Washington, in a statement released Thursday. “The indictment alleges the defendants deliberately did exactly that over a period of several years, and charged customers hundreds of thousands of dollars for doing so. These charges will hold them accountable for those crimes.”

The indictment alleges that the defendants sold trucks out of a Woodland-based automotive lot that then underwent a “delete and tune” at the Ridgefield shop, and also performed the service for customers who brought trucks in for work.

According to the indictment, the defendants downloaded, or caused to be downloaded, tuning software onto cellphones or computers. “The software was then used to modify, tamper with, and render inaccurate, the vehicles’ OBDS (onboard diagnostics),” the indictment alleges.

This work foils the monitoring system that — when pollution limits are exceeded — can cause the engine to shut down or operate in a “limp mode” that reduces speed and may prevent gear shifting.