This article is from the VW Performance FAQ, by with numerous contributions by Jan Vandenbrande others.
A:Not if you want to remain street legal, and unlike in the
early 70's, these devices have improved so much that the
loss because of it has become minimal or in some cases
removing the cat will rob you of power. Note: The
Catalytic converter on the SLC is rumored to be one of
the most free flowing of any VW, and will provide gains
when used on a Passat (or possibly other cars). New
Dimensions is toying around with this.
Note: In the US there is 20 000 US$ fine for messing
around with emmissions control equipment. Of course the
chance of being caught is rather minimal.
 
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