When I bought this car, it already had a HKS exhaust on it.  Unfortunately someone had chopped it and installed a smaller pipe and muffler.  Can you say moron!  A little while back I met a guy that was having problems with his Supra.  I tried to tell him it was an EGR leak (I could hear it) but his dad who hated the car (Honda guy) said it was more and he should sell it.  When he decided to sell his car I talked him into letting me buy the Random Tech cat and TenzoR catback exhaust. 

It wasn't hard to swap out the exhausts between his car and mine.  Everything met up to the factory hangers.  The cat is definitely high flow as it is hollow all the way through with slots around the edges to allow exhaust gasses to get into the honeycomb area. 

1- I had a heck of a time getting the very back hanger to come loose on his car.  There is a rod on the car and one on the exhaust that have knobs on the ends and a rubber assembly that slides onto each.  After using some WD-40, it came loose. 

1- The cat front bolts holes didn't quite line up with the HKS ones.  I had to grind out the holes a little to get everything together. 

After trading exhausts, my friend wanted a ride in mine to see what a good Supra should do.  I was surprised at the increase it power and reduction is spool up time, and he was upset that he had parted with his Supra.  I was doing 0-60 just over 5 seconds with a passenger.  I'd say it was well worth the money.

The stock exhaust sucks.

This is probably the single best HP per money upgrade that can be done.  Do it!