would i need 2 pre-cats and 2 cats... or could i just get 2 performance hi flow cats

 

If you want to keep smog legal, you wll need to have 4 cats in the system. Here in Cali, they do a visual inspection before they even hook it up to the sniffer. If even one thing is wrong, or missing..BAM. FAIL.

 

here where i live, i just run a nice straight pipe from header to muffler, then straight out the passenger side of my 2.3....love where they dont check emissions at