cataltyic converters - replacement options

[excursion]

Hi everyone, what are the options for either removing or improving the cats?

Does removal throw a CEL? I know there are secondary o2 sensors behind the cats, so does cat removal actually affect the engine management in a negative way....or are the probes there for further fine tuning of the mixture?

If I don't go the test pipe route, what are the other options available?

TIA,
Mark