The factory stainless basically will outlast the life of the car, however, the welds are not stainless and it pretty much gets nasty as it's REALLY not a true stainless. It is a higher grade quality steel but it still will rust eventually.
The factory Fiero exhaust is mandrel bent, which is excellent for performance, the Ocelot is NOT mandel bent. The Ocelot exhuast however is a full 2" exhaust while the stock exhaust is a 1-7/8" exhaust. They are nearly identical in performance due to the fact that the Ocelot has a larger diameter pipe, but the stock Fiero exhaust is mandrel bent, so there is literally almost no gain except in the very upper rpms. It will sound a bit different (slightly deeper) and it looks newer too.
The angled pieces that hold the springs which allow the factory exhaust to properly hang from the brackets on the subframe do not exist on the Ocelot, so you'll want to cut those off your old system. Typically though, muffler shops just cut those off and weld in some generic exhaust mounts. That's ok if you don't care, but if you want it to remain original, then make sure they don't do that.
Also, the aftermarket tips that typically come with the Ocelot exhaust look more like the tips that come off the 4 cyl Fiero (or more specifically, the Fiero Formula). You'll probably want to keep your factory exhaust tips by having them cut off the original exhaust and re-welded onto the flanges from the old exhaust.
Although you won't really gain any performance, it's more or less a necessity if you still have the original exhaust at this point.
You WILL see a substantial improvement in power if you go with the Fiero Store's aftermarket "high flow" catalytic converter and header pipe. It flows MUCH better than the stock cat. You can expect a 4-5hp improvement over the stock cat. Chances are though, this has already been replaced too...
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Todd,
2006 Pontiac Solstice
2004 Volkswagen Beetle Convertible (Wife's Car)
2002 Ford Crown Victoria LX
1987 Pontiac Fiero SE / V6 (3.2) 5-Speed
1984 Porsche 944 5-Speed
1981 Pontiac TransAm (Olds 455BB)
1973 Volkswagen Type-2 Transporter
