3-inch cat back on stock 2g

[eclipsegst3131]

How big of a cat back system can I put on my stock 2g GST...I want to do a 3-inch but fear it won't fit the stock Cat. So basically I ask, how big can I go before I have to replace other things with bigger parts.

Another question...If I got a turbo back exhaust how big could I go with that before I have to replace parts. I want a 3-inch really bad, but if I have to go with a 2 1/2 - inch than oh well, I just don't want to have to buy more parts for me to get this...

Thank you for any of your help.

 

[Lord Khan]

If you get a 3inch cat-back, most of them come with a 2.5 inch flange to fit your stock cat. If you want to ever upgrade to a 3inch cat, get the shop doing the work to cut off the 2.5inch flange and weld on a 3inch (this is what most people do if they don't go turbo-back from th e beginning). I have a Thermal 3inch cat-back but my cat, and downpipe are still stock. When I upgrade, I will have to get them to cut that 2.5inch flange off.

If you go 3inch turbo-back from the start, only things you will replace is the stock turbo-back exhaust. The downpipe will mate up to your stock 02 housing. No problem.