I'm putting dual exhaust on my 1997 Mazda B2300 with a Ford 2.3L

You will get a "Check Engine" light and the computer may go into a "limp" mode (decreased performance). The second O2 sensor detects how the Catalyst is performing. Most muffler shops split the exhaust after the Cat for this reason.

put the splitter out to two AFTER all that smog jazz~ little tube cutting and welding...junior level welding~

So, what I should do is cut the cat in half, and take the back half and weld it back into the exhaust?

no one really looks UNDER there, I'm sure there is enough real-estate there....you could chop a couple of inches out of the existing system if you needed MORE room for the split----the chrome tips will look the same~! the last device in line is going to be your catalytic converter...start at the exit flange...'nuff room...it's a pickup!

No. don't touch the cat~

start your split at the exit flange...don't think there are ANY more sensors after that.

just like Tracy asserted, do the modifications AFTER the catalytic converter...this way will not affect the computer's performance...then will be simply decorative...could put glass packs or chrome tips or anything you want at that point.~

Well, if you're in California, you have to smog check it every- other year and yes, they do look under the car. DON'T TRY TO CUT THE CAT.

everybody loves the "thrush" bird logo, they used to give them stickers when you bought a glass packed thrush~

OOooohhhhh! Purdy!

get your welding rod at your dry cleaners...they've got an ample supply of wire hangers they'll give you for free...or next to free~

kids these days~