Have you looked into aftermarket cats?
Have any friends with a welder and torch?
Someone not in business, but a buddy who would help you
for a case of beer or a gift certificate?
Probably wouldn't be hard to fab some kind of shield to protect the
pipes and the hangers. Ideally, you buy some hardenable steel from
Granger or Fastenall. Get it to shape harden the most likely to be cut
spots.
You can't make it theft proof.
But when they see thicker steel protecting the thin stuff,
And if the saw just won't cut.
They aren't going to keep going.
They very well might damage something else.
