blue thunder06

idk where you get a piece of an exhaust system from a big car manufacturer, that being "Cadillac" but no you do not have to take them off if your going to put on a performance muffler. like magnaflow, borla, flowmaster etc...... now it is illegal to take off the catylatic converters, you can actually be fined a very substantial ammount if a cop finds out you do not have catylatic converters on your vehicle. as mentioned before, 04 and 05 models have four cats, not 06 and possibly not 07. what you can do if you choose not to spend the money on hi-flo cats is take off the two rear cats and have a pipe welded on to fill the place of the cats, that is okay because they wont turn on the check engine light.

2000fan

Lol I hear it too everyday. they mainly call it cadillac convertable