I know you are on a budget, gutting the cat is free. OBD1 has no after cat O2 sensors and you will see a few hp too.

Gutting procedures(must be strictly followed - haha):
(1) Unbolt & remove exhaust from back of cat
(2) Take a hammer or small sledge with a piece of rebar and beat the crap out of the honey comb crap inside the cat
(3) Shop vac or pull out the pieces (This takes about an hr)
(4) Start car before installing catback to make sure you get all the pieces out and to hear it with no muffler
(5) Install catback