Picked up this 90 4Runner. Besides CV’s it needs exhaust bad. Everything behind the Catalytic Converter is leaking bad. Must be 10 holes in the pipe and muffler. A quick google search found a Cat Back systems from LCE performance. I’m sure there are others as well. Is there any power gain or performance benefits from a system like this? Or would I be better off saving a few bucks and just have a local muffler shop fab something up? Oh yea, it’s a 3.0.

 

I've been told that even with headers and free flowing exhaust that the 3.0 liter is still the 3.slow, you won't get much of a performance gain at all.
It isn't likely to be worth the extra money to get an aftermarket setup unless you are doing the work yourself and don't have benders and pipe expanders and such, then you could end up cheaper than going to a shop and paying their labor to build your exhaust from scratch.

 

Jump on youtube, listen to a muffler of your choice, order it online (summit racing) and take that to the exhaust shop and they'll charge you $100 to fab a tailpipe up with the muffler.

This is the most viable solution.