From EPA. Gov:
"Under federal law, catalytic converters may not be removed and replaced with "converter replacement pipes' by any person. The 1990 Clean Air Act Amendments even prohibit private individuals from installing "converter replacement pipes" on their own vehicles. Anyone who installs such pipes would violate section 203(a)(3)(A) and (B) of the Clean Air Act (Act).
As for "off-road" use only:
The federal [catalytic converter] tampering prohibition pertains to "motor vehicles, " which are defined by section 216(2) of the Act as "any self-propelled vehicle[s] designed for transporting persons or property on a street or highway."A light-duty vehicle manufacturer certifies an engine-chassis configuration as meeting the applicable emissions standards for motor vehicles manufactured in a given model year, and it is not legal for anyone to "de-certify" a motor vehicle for "off -road" use."
In other words, if you want the car to legally be driven on highways, streets or even off-road, then no, you cannot remove the vehicle's catalytic converter.
If you never plan on selling or registering the vehicle and decide to buck the law, then yes, you can remove the catalytic converter. Depending on the emission control setup on the vehicle the "check engine" light will illuminate and fuel-air mixtures may be impacted. In general, though not always, removing a catalytic converter reduces pressure in the exhaust system thereby improving performance and fuel economy.
To make a long story short, yes, it will run. Possibly better than before.
Tuesday, September 7th, 2010 AT 8:22 PM