Okla. Stat. tit. 47, § 47-12-423: Emission control system - Disconnection, alteration,

modification, or replacement.

A. On any motor vehicle originally designed and equipped with

an emission control system such system shall be maintained in good

working order.

B. No person shall:

1. Disconnect any part of such system except temporarily in

order to make repairs, replacements, or adjustments;

2. Modify or alter such system or its operation in any manner;

or

3. Operate, and no owner shall cause or permit to be operated,

any motor vehicle originally equipped with such system while any

part of that system is known by the owner to be disconnected or

while that system or its operation is modified or altered in any

manner.

C. The provisions of this section shall not apply to any

disconnection, alteration, modification, or replacement of a nature

intended to increase effectiveness of the system in controlling the

emission of air pollutants.