Defeat device
Defeat device means an auxilary 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 vehicle operation and use, unless:
(1) Such conditions are substantially included in the Federal emission test procedure;
(2) The need for the AECD is justified in terms of protecting the vehicle against damage or accident; or
(3) The AECD does not go beyond the requirements of engine starting.