The replacement of the original catalytic converter with any aftermarket unit is limited by the Federal Clean Air act, as outlined below.  It must be understood that installing an aftermarket performance exhaust component such as the exhaust manifold or downpipe that includes the catalytic converter can only be done on vehicles intended for off-road use only and can never be driven on the streets.   



To any person repairing or installing any exhaust system, the Clean Air Act, as amended 1990, requires that:


1. If the vehicle is missing a converter; *

2. If a State or local inspection program has determined that the existing converter has been lead-poisoned, damaged, or otherwise rendered ineffective and needs replacement. Retain a copy of this statement from any government inspection or enforcement agency for your records;

3. If the vehicle is over five (5) years old, or has more than 50,000 miles, or eight (8) years old or 80,000 miles for 1995 and newer model vehicles, AND a legitimate need for replacement has been established and documented.* This situation normally would include only plugged converters or those damaged to the point where unrepairable exhaust leaks are present. See * DOCUMENTATION REQUIREMENTS below.

Catalytic converters are emission control devices which are designed to last the life of the vehicle and do not normally require replacement. Furthermore, if the vehicle is properly used and maintained, original converters are covered by the emissions control warranty for 5 years/50,000 miles, or 8 years/80,000 miles for 1995 and newer models. Federal law prohibits any person from replacing these devices except under limited circumstances (listed above).


In order to establish and document that the circumstances permitting replacement of an original or missing converter with an aftermarket converter meeting the required performance criteria exist, the Installer must complete the INSTALLER’S WARRANTY SHEET. The installer and the vehicle owner must sign the statement establishing and documenting catalytic converter replacement justification.

- A copy of the completed warranty sheet must be attached to the invoice and retained by the installer for six (6) months.

- Also, the replaced converter(s), if any, must be retained by the installer for at least fifteen (15) days from the date of installation.

- The installer must install each replacement catalytic converter according to EPA policy, as described in the INSTALLATION REQUIREMENTS.