The knocking isn't on the swaybar. There's plenty of clearance there. It's on the floor of the car. And it occurs because the buddyclub header is a two piece header, meaning the spring bolts that join the two pieces allow for some slight movement. I know this because I was under the car and had it demonstrated to me by the mechanic. My concern wasn't where the knock was coming from, it was whether it was the cause of the CEL. But it's been established that it's my cat (or lack of). So thanks guys for clearing that up, I'll look into the defouler asap.

As for buying toda headers over buddyclub, you have to have rocks in your head. Adrian quoted me approx. $2500 for the toda header, cat and ep3 sway. I got my BC header for 1150, and I don't need another swaybar. Anyone who pays nearly 1500 more for a toda header is an idiot. Unless it's going to make me twice the power, it's a huge waste that could be spent on other parts. And I know for a fact it won't make anywhere near twice the power. Heck, you'd barely notice the difference with a kpro, which is next on the list. Sorry to burst your bubble pal, but value for money, and for a street driven car, the BC header eats the toda header.