According to court documents, Sinister Diesel, from its 2010 incorporation to April 2020, manufactured and sold parts intended to be installed on motor vehicles, particularly diesel trucks, to enable “deleting” the trucks by removing or disabling the trucks’ emissions control systems. Various products, referred to as “delete devices” or “defeat devices,” are used in the process of “deleting” a vehicle. Sinister often sold its products as part of “delete kits,” sometimes bundled with “delete tunes.” The delete tunes were software produced by another company which could alter a diesel truck’s on-board computer to allow a truck with its emissions controls “deleted” to appear to run normally.

Through its employees, Sinister Diesel reached agreements with other companies that manufactured tuners or tuning platforms to sell their products bundled together. Sinister would often advise customers on other needed parts for their deleted vehicles to run properly with Sinister’s delete kits – such as a tuner or tuning platform and delete tunes — and sell them those products, too. Sinister also counseled customers on how to evade state emissions tests.