I'm looking to replace my exhaust (several holes) and was wondering the cheapest way to gain power and a bit of a note on my TE 2.4l 4cyl.

Would some sort of VRX muffler/ exhaust system fit/work

not sure on te 4cyl but the tj v6 has the same system between the exec and vrx only difference being the rear muffler

yeah, pretty much all 3rd gen v6 exhuasts are interchangeable, but not sure about the 4cy.
You should be able to get a muffler shop to weld you up a 2.25 inch or something similar, with maybe a hotdog and a lukey sports at the back. As long as your cat is ok, it will cost around 550-600 (using a quality muffler, a generic muffler may bring it down to more like 450)

You could just replace the rear muffler with a high flow muffler, possibly a redback/lukey (depending on the brand they use) will set you back about 250-350 depending on where you go.. phone around and get quotes and find the best price :). It won't make quite the performance difference that a full sports exhaust will do but if you're short on cash, thats the 2nd best thing to do.

the stock vrx/sports muffler is a lukey muffler will set u back 300ish from mits for genuine one bolt straight on

yeah, pretty much all 3rd gen v6 exhuasts are interchangeable, but not sure about the 4cy.
You should be able to get a muffler shop to weld you up a 2.25 inch or something similar, with maybe a hotdog and a lukey sports at the back. As long as your cat is ok, it will cost around 550-600 (using a quality muffler, a generic muffler may bring it down to more like 450)

So what is the cat exactly...

the cat is the catalytic converter (standard on all aust delivered cars from 86??) basically it uses a chemical reaction between the exhaust gases and the material inside the cat to filter out some of the more harmful gases in the exhaust.
Illegal not to have one if the car is newer than 86. Replacement cats are expensive not sure on $$$ though

the stock vrx/sports muffler is a lukey muffler will set u back 300ish from mits for genuine one bolt straight on

Does the TJ sports muffler fit to a 3.0 engine?

I had a full redback system fitted for $380. I think thats probably the best bang for buck. But in saying that I havent heard of anyone else being quoted a price anywhere near as good as that.

again not entirely sure... as mine is the 3.5 but im guessing the rear muffler is standard across the board??? anyone???

Where abouts are the holes, it might just be cheaper to get a muffler shop to fit a generic muffler they've got laying around, exhausts are pretty pricey.