[SumAznGuy]

Originally Posted by AzNightmare

I don't want to deal with swapping out a test pipe every time my car goes in for aircare.

In theory, aircare is supposed to be over by Jan 1 2015 so you may not need to worry about this anymore.

Based on the Borla picture posted above, I see 2 "bigger" sections. But I'm getting confused if one is a muffler, or a cat, etc?

Is the first diagram a stock 2005 mazda3 exhaust system?
I can see the (1) is the primary built-in cat you mentioned. What is the (2)?

Is the second diagram, is the (1) the muffler? And is that the entire thing I'm replacing with the aftermarket exhaust?

Part #2 of the first picture is the resonator, which is the first round part is the second pic.
Part #2 in the second picture is the muffler. From that point on, it is all pipe and the bigger tip.

If I keep my OEM cat that's built into the exhaust manifold, can I get the Corksport test pipe version, but just not use the test pipe, and attach the rest of the exhaust system to my OEM cat (without welding)? I don't think spending $200 for a hi-flow cat seems necessary, but using the test pipe makes my car not street legal, too loud, and smell bad.

You still have the stock cat in the exhaust manifold so you won't get the stink. But it doesn't mean the test pipe will not get you a VI or a fail from air crap because police officers/Aircare employees may not know the exact specs of a stock 05 Mazda 3 exhaust system.