The diesel tuning business has changed a lot in the last four years. The Environmental Protection Agency is scrutinizing everybody from huge engine manufacturers like Cummins to small tuner shops.

PORTLAND, Ore. (KOIN) — The federal government is going after a Hillsboro business, accusing them of modifying hundreds of diesel trucks to disable pollution control systems. The U.S. Attorney’s ...

A Roseville-based truck parts manufacturer on Tuesday agreed to pay $1 million after pleading guilty in Sacramento federal court to conspiracy and for making and selling illegal “defeat devices” that ...

The owner of a 2008 Dodge Ram 2500 with a modified diesel engine has taken to Facebook to warn others that the state of New Jersey may be trawling social media, looking for trucks that do not comply ...