I'm getting a header and will be welding an aftermarket catalytic converter to it. Does the cat need any type of break in? I'm planning on installing it early next week, but I have a track day next friday (4/25) and I don't want to damage the cat by running it hard so soon if it needs a break in.

 

it may smell for a bit, but no break in is required.

Matt

 

No, not really... your exhaust tone will change over time as carbon deposits line the header and rest of the exhaust though. Most of the time it gets deeper. Cat's require no break in though.

 

Great, that's good news. Thanks for the quick replies.

I'm still contemplating putting the header/cat on so soon before the track day, I usually don't like to make big changes before a track day. It would suck to throw a CEL or have something leaking.