The precats are $$$ because they're integrated into the exhaust manifolds. Gutting is a good route, but you've gotta be patient so you don't kick any material up into your engine - or do it off the car to be safe. MIL eliminators must be purchased & instlled by YOU to get rid of the CEL. Not difficult, search for a good source on these boards & the net. Another choice is to purchase modded manifolds & have them bolted on. You can get them cheap, then do it yourself if you're mechanically inclined, or hire it done for a couple hundred. Again, MIL eliminators by U will be needed.
The main cat: You can get a hi-flow unit from just about any muffler shop installed for well under $200, shop around and stay away from Meineke - they're usually over priced & the last few that have dealt with their chain have gotten very bad advice & products. You'll still be smog legal with a main cat once the engine is warm.
