Why not borrow a stock exhaust & stick it on, not exactly a huge job & you'll have no problems with the cat or noise, this is the best & easiest way to remove tint, I took some 5% off a few months ago, took me about 1hr all up with a bit of waiting in between, cloudy ammonia is only a couple of dollars at any supermarket.

http://www.tintcenter.com/articles/bt_removal.html

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Beaten up old 98 Gen 2 Liberty, 13.0, stock V3 STI running gear.
07 Transit motor home
69 VF & 70 VG Valiants needing full restoration
Yamaha Zooma 50cc rocket hopefully going with the Transit.