will running without catalytic converter change drivabilty

You get shunned by the hybrid community and then a crazy expensive, ticket for, tampering with emissions equipment.

 

You will get the CEL coming on because the sensors will not be working.
You will not hurt the engine, but your fellow man will recieve more polution.
If your CAT is clogged, and you need to temporarily remove it until you can get it replaced, you should be OK, but be sure to replace it ASAP. There are some less expensive after market ones available.

 

Without the cat the car will go into "limp home" mode. It will burn more fuel than it needs to. It may eventually foul the plugs. Removing the cat is a bad idea. Ignoring the legal ramifications.

 

David:
I think the oxygen sensor would still be in place, so the air/fuel mixture would not change. There are actually 3 CATs two small ones, and a large one. The sensor is between the 2 small CATs. If the larger CAT only is removed, the engine should not be effected. I'm not sure what the OPs motivation is for asking the quesion.

Howard

 

You can get a ticket for that?
Oh....I get it. Some states have VETs.

Yeah, Yeah....I know. Believe me. I ride a bike. As much as I'm not a big government kinda guy....I actually wish they did the VET thing down here. Instead, we're a dumping ground for all of the used cars in the US that don't pass the tests in the states that DO have a VET program.

Anyway....to the OP:

If you do have to bypass your catalytic converter temporarily while you're waiting for a new one, or rolling pennies for the repair, or whatever...it won't hurt your car...but it is illegal, even in the unwashed heathen states that do not have a formal VET program.
Just go ahead and get it fixed.
It's gonna be fairly cheap...all things considered, and you gain nothing from running with it removed from your car.