Are all mini trucks that have been modified to nonroad use acceptable under the Clean Air Act?
No. The only acceptable modifications from on-road to nonroad are those that allow mini-vehicles to perform in a manner consistent with EPA-issued guidance; have been determined by EPA to be sufficiently permanent and tamper-proof; and that have been approved by EPA in writing. Vehicles meeting these criteria may qualify for an exclusion from the CAA. See http://www.epa.gov/otaq/imports/index.htm#contacts.