Has anyone heard of performance cats that are legal? I was at a shop today getting my ford racing headers installed and the guy asked me if i had the performance ford racing cats too? I really dont know to much about this stuff so give me some help. Thanks

 

By letter of the law no aftermarket cat is legal.
Emissions laws clearly state that altering the exhaust in any way, including replacing the cats with aftermarket cats or changing their position in the exhaust system is a violation.

 

You are allowed to change cats if they are in some way damaged, ie you were in an accident. If the cats stop functioning properly, you can chenge them as well. You can put hi-flows on then....but save the old cats just in case.

You could take a pipe wrench and go to work on them, but I dont think that is what the EPA had in mind!