Opinions on using test pipe or free-flowing cat

test pipe since you dont need to worry about smog. It'll feel a bit nicer

The test pipe will be cool for a couple weeks then the sound will anoy you to the point where your gonna buy a high flow cat anyways, so delay your purchase an extra week, save up 50 more bones, and buy a GOOD high flow cat.

It depends on your catback system. I had a catpipe on my '91; combined with a Mongoose system and Tanabe header, it sounded great

http://hometown.aol.com/Saz9961/AndyatKirkiston.wmv

I know on other systems, it might not be as nice though. I never suffered a dirty bumper with this setup.

The stock factory cat was already a free flow design; the aftermarket ones do little to improve on this, though they are undoubtedly better than a generic can with flanges welded on. After 60k mls, the stock cat starts to deteriotate.

my stock cat is completely dead at 90k miles, i have stock header and after the cat, a BSP candoo, and i get a nice blackened bumper a couple of days after a wash

Use a cat unless your running FI. The sound will be annoying and your most likely going to lose torque with a test pipe.

When I had a turbo on my 1.6L, I ran a test pipe and loved the added power and sound.

I think my cat may have already failed, 'cause I have a nice bumper stain if I don't wash my car weekly. It's been raining ALOT in southwest Florida and my only chance to wash is on the weekends. She's my daily driver, and it sucks not to keep her clean, if you know what I mean. But, I will continue building a great Miata that I will NEVER sell, and this is just one little step in the ongoing process that I plan to share with everybody on CR.net . Thanks for all your help!

By the way, no turbo yet, but VERY soon

made a HUGE difference on my turbo miata. Dont know about n/a though

the exhaust was kinda stinky for a while (rotten egg-ish) but went away after a month or so ... sounded more throaty w/o the cat too, although I also went to a Mazdaspeed exhaust as well.