want to switch over to td`s (w/h-pipe )from the LM setup, my question is , should i run them with or without cats ? and also i want them dumped u think it would look stupid with no pipes in the cutout of rear bumper?

 

depending on your states laws and how loud you want it to be will determine if you want cats or not....also remember most states, if they require cats...you cant dump them at the axle....and mine doesnt look stupid....looks mean

 

I live in maryland and yes we do req. cats but nobody runs them, but I like to drive mine daily, maybe i`ll run some gutted ones just in case. as far as emissions my tuner takes care of that.

 

I would go with no cats..

 

is there anything illegal with having my exhaust dumped or does it have to exit out the rear?

 

Im pretty sure there is nothing illegal with dumping the exhaust before the axle, unless the state your in requires the sniffer test. I am running no cats with dumped exhaust and love it. I would reccomend riding in a car with dumped exhaust so you can hear the difference before purchasing it. Its loud

 

cats are required everywhere in the US, as per federal regulations. also, the exhaust has to extend past the gas tank. (most states).

 

I believe in most states the exhaust is required to exit out the back of the car to be legal. I may be wrong though. But who on here has a 100% legal car?

 

If you are concerned about keeping your exhaust legal you could contact your local DPS and they should be able to tell you what is and isn't allowed.

 

in some cases if you run your cat you will make more hp/tq with it than with out it depending on if it is a good cat back or not