part_subject: "CONTROL OF EMISSIONS FROM NONROAD SPARK-IGNITION ENGINES AT OR BELOW 19 KILOWATTS"
subpart_code: "B"
subpart_subject: "Emission Standards and Certification Provisions"
section_number: "90.111"
section_subject: "Requirement of certification—prohibition of defeat devices."
cfr_reference: "40 CFR 90.111"
title_name: "Title 40"
title_subject: "Protection of Environment"
parts_covered: "Parts 87 to 95"
revised_date: "Revised as of July 1, 2017"
publication_date: "As of July 1, 2017"
contains_description: "Containing a codification of documents of general applicability and future effect"
publication_info: "Published by the Office of the Federal Register National Archives and Records Administration as a Special Edition of the Federal Register"
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(a)An engine may not be equipped with a defeat device.
(b)For purposes of this section, “defeat device” means any device, system, or element of design which senses operation outside normal emission test conditions and reduces emission control effectiveness.
(1)Defeat device includes any auxiliary emission control device (AECD) that reduces the effectiveness of the emission control system under conditions which may reasonably be expected to be encountered in normal operation and use unless such conditions are included in the test procedure.
(2)Defeat device does not include such items which either operate only during engine starting or are necessary to protect the engine (or vehicle in which it is installed) against damage or accident during its operation.