Notwithstanding any other provision of law, any motor vehicle of mosquito abatement, vector control, or pest abatement districts or agencies, any authorized emergency vehicle as defined in Section 165, except subdivision (f) thereof, and any ambulance used by a private entity under contract with a public agency, is exempt from requirements imposed pursuant to California law and the regulations adopted pursuant thereto for motor vehicle pollution control devices.
Source:
Section 27156.3, https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=VEH§ionNum=27156.3..