Catalytic converter

Might cost you around 4 hundred bucks, labor and parts. The cheapest universal cat I saw was around 130 bucks, they go up from there. Around a 2 hour job. If the shop charges 100 bucks an hour, 200 bucks for labor not counting the parts.

If you have a basic set of tools, wrenches and sockets, standard and metric sizes. I don't see why you couldn't do it? Some of the nuts/bolts could be rusted, that might cause a problem. If you have an impact wrench, that might help?