I have a '99 GTP with newly installed Speed Daddy headers. I have yet to deal with the catalytic converter problem though. I was initially just going to have a shop weld the factory unit in but the SD downpipe is 3" and the cat is 2.5" so I thought I'd might as well go for a cat'd 3" downpipe from ZZP since the price seems pretty reasonable.
http://shop.zzperformance.com/store/...Downpipes.aspx
Until I saw this "This downpipe is not compatible with any aftermarket headers, it is designed to fit the stock OEM rear manifold."
What are my options then?
Thanks people.
