Jonathan Martel Discusses EPA Guidance on Aftermarket Diesel Sensor Removal with Inside EPA
Jonathan Martel, co-chair of Arnold & Porter’s Environmental practice group and a former attorney at the U.S. Environmental Protection Agency’s (EPA) Office of General Counsel, was quoted in the Inside EPA article “DOJ, EPA Appear Split Over Legality Of Aftermarket Diesel Sensor Removal,” which examines questions surrounding EPA guidance on diesel exhaust fluid (DEF) sensor removal and the government’s ongoing enforcement posture in aftermarket diesel tampering cases.
Jonathan disagreed that EPA and DOJ are “split” on the issue, but noted that EPA’s recent public statements have created “mixed messages” regarding the agency’s position. He added that EPA’s guidance is intended to encourage manufacturers to transition from direct DEF quality sensors to alternative NOx-based monitoring systems, rather than abandoning emissions controls altogether.
He also observed that aftermarket software replacing DEF sensors with effective NOx-based monitoring systems “would likely have a good defense to a tampering allegation,” while cautioning that EPA’s messaging may have contributed to confusion about the scope of permissible modifications.
