X2! Magnaflow cat and two new NTK 02's and you're good! The y pipe needs to be welded so it's not just a bolt on.

 

The cat on my truck has 2 inlets and one outlet, and the O2 is basically right where the two pipes come in, you can't really straight pipe that. Instead of trying to fab something you might as well just spend the $60-$80 for a new cat.

I've heard of some people gutting their cats but this is usually when the cat is bolt on and easy, these are welded. Plus you truck should have a rear O2 you will probably get a code if you do.