When the cat is removed your car almost certainly violates noise ordinance, so it's undrivable unless you know someone quick with exhaust pipes and clips or a w

When the cat is removed your car almost certainly violates noise ordinance, so it's undrivable unless you know someone quick with exhaust pipes and clips or a welder. So, yeah, you can drive a car without a cat, but not without a muffler (generally). Fix it tickets still incur a monetary cost.