Replacement downpipes??

Hi there!

Haven't been here for a while... I started my zed up the other day for the first time in about a month, and almost immediately it started puffing out from the passenger side of the downpipe, where that little branch is welded into the main downpipe. (Can't remember what it's for, but I did read somewhere...) Anyway, it's an HKS stainless exhaust, but for some reason these little pipes look to be mild steel so have rusted at the weld. What are your recommendations for a set of downpipes? The ones fitted at the moment have a small baffle in the middle of the pipe but I am happy to fit straight through 'de-cat' pipes (it never had cats anyway). I don't want to buy new exhaust headers (or flanges or whatever you call them), trying to keep the cost down.

Cheers

Derek