Adjustable Parameter
Adjustable Parameter means any device, system, or element of design which is physically or electronically capable of being adjusted (including those which are difficult to access) and which, if adjusted, may affect emissions or engine performance during emission testing.
Source
40 CFR § 94.2
Scoping language
The definitions of this section apply to this subpart. They also apply to all subparts of this part, except where noted otherwise.