Join Date: Sep 2009
Location: Brownsville, TN U.S.A.
If my CAT went bad and I could not afford to get a new one I would gut it. Here's the thing, without the cat's guts you might throw a CEL, in fact I am sure that you will, and you may see a minor drop in mpg and power, but if you drive around on a plugged cat you will kill your motor.
I know, some think an engine "needs" back pressure, or it will not run. That is not exactly true. An engine does not "need" back pressure, however they are set up (timing) from the factory to compensate for the back pressure. This is why when you remove the back pressure the car will not feel exactly right.
Still, that's a hell of a lot better than a toasted engine from a plugged cat.