I keep hearing about how clogged cats can kill your engine and that I should either hollow them out or rip them off and put in a straight pipe. How can I tell if my cats are clogged or not? How do you hollow them out and what effect would that have? I've got a 12A stock with a cold air ram.

 

The cat will cause your car to lose power at speed if you are clogged. The first gen used a pellet converter instead of a monolith for the main unit. It spits the pellets out over time. Better to leave it on as you get very loud exhaust with a pipe.

 

My cats were clogged to the point where my car would net even rev past 500rpm, and would die if i touched the gas. Hollowing them out is very easy, just remove that section of the exhaust, and have some fun beating the carbon out of the insides with a hammer, crowbar, and a bigass screwdriver. At least those are the tools i used I bought my car in this condition, so i really dont know what the difference is, but i do know my car is running GREAT with no cats.

 

also, its not very loud, and i also have an exhaust leak.