Catalytic converter.

[Fiatracertracer]

What is the consensus on the cat... shall I keep it intact, gut it, or remove it and straight pipe it?

Is there any performance increase if the cat is done away with?

[whiteonyx]

Remove it, you get a couple of BHP improvement but best of all, a much better sound

[sergio1977]

I agree, I did it on mine and finished the tail pipe with a nice Ansa Performance Exhaust. The sound is great I am not sure if I am getting more HP but sure sounds like it.

[vandor]

You get 2-3 HP from removing the car - the Euro version of the Pinin Spider was rated at 3 more HP than the US version, and the only difference was the lack of a converter.

[Dawgme85]

When I switched SHELOB over to a 4-2-1 manifold and port-matched head, we removed the stock cat and I had a new muffler installed. When I came to pick her up at the muffler shop, the installer told me "it's a bit loud". I decided that was alright and took her home. However, over the next few days I came to agree, so the following weekend I returned and had them install a new low restriction cat, which quieted it down just enough. She still growls like a nice Italian car should, but not so much as to hinder conversation. HP seems to be plenty adequate, in any event, as she'll still pull to redline in at least the first 3-4 gears (I've only taken her up to about 105 mph, but there's still more available ). YMMV.

[Frog2Spider]

FYI for any interested ....

I have a near new ( installed for less than 30 minutes ) Test Pipe for the later model with the 4 bolt flange.
I paid $150 for it, and will sell for $100.
Contact me:
pro-frog@comcast.net

Dave.