Section 38391 Of Article 5. Emission Control Equipment From California Vehicle Code >> Division 16.5. >> Chapter 6. >> Article 5.

. No person shall install, sell, offer for sale, or advertise any device, apparatus, or mechanism intended for use with, or as a part of, any required off-highway motor vehicle pollution control device or system which alters or modifies the original design or performance of any such motor vehicle pollution control device or system.