catalytic

Hey, H3 2008 owner here, looking for advice on where to purchase some upgrades! Like, a catalytic converter shell, our GMC dealership does not offers the parts, but if I can buy it, they can install it, also looking to go LED for the Fog lights and the tail lights, any recommendations are...

Besides tight clearances, is there any technical reason not to individually replace each cat? Mine are shot, and constantly throwing code P0420/P0138 and won’t pass emissions. Probably doing the extender trick for the short term. At close to $1000 to replace both driver’s and passenger side...