Not to flame anybody but....tampering or removing cats from any originally equipped vehicle is illegal (federal emissions)...there are some grey areas that allow you replace cats 1. factory defect 2. 50,000 miles on the ticker and cats are found to be malfunctioning 3. accident has damaged cats beyond their function.
The fine if found guilty...$50,000 believe it or not, it falls under the emissions act under federal law.
On a lighter note, local laws also adhere to Federal guidlines but have lesser penalties, usually a fine and equipment repair order. The federal charge is not implied unless your found to have a substantial impact on the environment ( a shop that practices gutting cats...etc)
I would'nt suggest an O/R, it's not worth the hassle...with cats you might have an excuse (see above)..without, your S.O.L.
Just a little information...alot of us use high performance cat pipes...mine s an X (w/cats)
