Cat and Resonator Placement

[ACHTUNG]

Where and in what order would you place the cat and a resonator on a custom single 2.5" exhaust install on a M20? Is it best to put the cat just after the headers then the resonator or the opposite?

[NC325iC]

cat as soon as possible if youre worried about the environment

[e30this]

yup closer the cat the better.
Where do you find a 2.5 inch res? I could only find 1 7/8.

[ACHTUNG]

yup closer the cat the better.
Where do you find a 2.5 inch res? I could only find 1 7/8.

I just got a cheapo SS resonator on ebay. It's this one:

http://cgi.ebay.com/ebaymotors/2-5-UNIVERSAL-TEST-PIPE-RESONATOR-CAT-CATALYTIC-CON_W0QQcmdZViewItemQQcategoryZ33629QQihZ009QQitemZ190218577005QQrdZ1QQsspagenameZWDVW