Wis. Admin. Code NR § 485.06 : Department of Natural Resources —Environmental Protection Air Pollution Control — Control of emissions from motor vehicles, internal combustion engines and mobile sources; tampering prohibition — Tampering with air pollution control equipment

(1) No person may tamper with or fail to maintain in good working order any air pollution control equipment which has been installed on a motor vehicle by the manufacturer prior to sale unless the person repairs or restores the equipment or replaces the equipment with new identical or comparable tested replacement equipment. Catalytic converters must be original equipment or EPA-certified equipment except as specified in sub. (2). Air pollution control equipment includes but is not limited to:
(a) Positive crankcase ventilation equipment.
(b) Exhaust emission control equipment.
(c) Evaporative fuel loss control equipment.
(d) Any control equipment operating on principles such as thermal decomposition, catalytic oxidation or reduction, absorption, or adsorption.
(2)
(a) Notwithstanding sub. (1), any person may replace the catalytic converter with aftermarket equipment certified by the U.S. environmental protection agency (EPA) on the following categories of vehicles:
1. All vehicles of model year 1994 or earlier.
2. For vehicles of model year 1995 or later, those vehicles which are at least 8 model years older than the current model year, or those vehicles with more than 80,000 miles on the odometer.
(b) If the catalytic converter is replaced, the owner of the vehicle shall provide a receipt or other evidence showing that the replacement converter has been certified by EPA.

Wis. Admin. Code Department of Natural Resources § NR 485.06

Renum. from NR 154.17(2), Register, September, 1986, No. 369, eff. 10-1-86; renum. (intro.) to (4) to (1) (a) to (d) and cr. (2), Register, July, 1989, No. 403, eff. 8-1-89; CR 05-072: am. (2) Register March 2006 No. 603, eff. 4-1-06.