In one of the previous posts it was mentioned that the B15 has a close coupled cat. This is absolutely true. I just finished looking at it with the heat shield off and it is all ONE PIECE. This means problems for those of us in Az w/the IM 240 emissions test. If the parts used are not CARB approved there could be a problem. To put the header on you have to remove the cat. If the cat. isn't on the car you can fail during the visual inspection. Ok suppose you want to relocate a cat. after the headers? While I am going strictly off MEMORY and I COULD BE WRONG, that is also a no-no. Why? Because to do so requires that you remove a properly functioning cat. to put the new cat on. The only times you are allowed to replace a cat. is if it is not working right or beyond a certain number of miles on the car. I doubt that any of our cars qualify under those two. Also if the cat. is relocated you could fail the visual inspection because car manufactures have gone to the close coupled cat. for a reason. It seems that one of the worst times for a car to emit pollution is right at startup. To meet the new requirements they put in a second cat.--right where it is a pain in the *** for us. Moving it could fall under the rule about tampering, which is illegal. So unless the headers and cat. you get are CARB approved we may be totally screwed. In fact, we might be screwed even if they are CARB approved. All I can say is I hope I am reeeeeeeeeaaaaalllllly wrong about some of the things I have mentioned. If anyone knows different PLEASE let us know! I couldn't find a damn thing on the internet when I looked.