Catalytic Converter Options

How important is it to replace the catalytic converters in the TR? There are two pre-cats and two cats and I'm told that the Hyperflow replacement parts are $4,500 alone.

My state doesn't test for emissions, but I don't want to needlessly harm the environment, or my car. I've read through the search feature, but there seems to be a disagreement about what should be done.

Some suggest that if you ignore the cats you risk some particles from the cats passing into the muffler, causing problems. Others suggest drilling out the cats themselves, but that seems to be a solution with lots of unintended consequences.

I have the stock exhaust, which I prefer. I don't want to change the exhaust sound, nor do I want to harm my car, but the price of replacement cats and labor is more than 10% of the value of the car.

Is there an alternative that the professional mechanics on this forum find acceptable?

Thanks in advance.