The owner of a Pennsylvania diesel repair and towing company is facing multiple charges for allegedly performing or facilitating hundreds of “deletes” or “tunes” on commercial trucks.
On June 3, 2025, a federal grand jury in Pennsylvania indicted Matthew Caroluzzi and his company, Matt’s Heavy Duty Mobile Diagnostics and Truck Repair and Heavy Towing (Matt’s HD) on nine counts of violating the Clean Air Act and one count of conspiring to violate the Clean Air Act and aiding and abetting, according to a news release from the U.S. Department of Transportation – Office of Inspector General (DOT-OIG).
Caroluzzi, Matt’s HD, and co-conspirators are accused of collecting approximately $1 million from customers by “performing, and aiding and abetting the performance of, deletes and tunes on more than 700 diesel powered trucks.”
Officials detail the accusations against Caroluzzi and Matt’s HD:
“Matt’s HD was a Pennsylvania certified vehicle safety inspection station that performed repairs and maintenance on commercial motor vehicles including heavy duty and medium duty diesel-powered trucks and other vehicles. Caroluzzi, Matt’s HD, and others allegedly performed hundreds of “deletes” of hardware components of commercial motor vehicle emission control systems and software “tunes.” Hardware alterations to emissions control systems are often referred to as “deletes.” These deletes tampered with the monitoring function of diesel trucks’ on-board diagnostics (OBD) monitoring systems, thereby enabling numerous vehicles to function while emitting higher levels of air pollutants into the atmosphere.
Caroluzzi and his co-conspirator employees recorded “deletes” and “tunes” as “deletes” on work orders and invoices, but later allegedly disguised the illegal conduct by using code words such as “reprogram,” “re-flash,” and “ECM repair” on Matt’s HD paperwork. The act of rendering an OBD system ineffective is commonly referred to as “tuning” or “flashing.””
DOT-OIG is working with the Environmental Protection Agency-Criminal Investigation Division on the ongoing investigation.
