5280CLS

I have had mixed results with aftermarket cats and prefer OEM over anything aftermarket. With the current set up of the mid length headers , the only pace to weld in a primary cat is around the transmission oil pan area plus I would need to extend my primary and secondary o2 sensor wires. Compared to factory, it's much further away from the heat source of the exhaust ports which then causes the cat to work inefficiently. I found a set of stock headers already so if I have to build a custom set up I will try and replicate as close to OEM as possible. The state will let a modified exhaust drive on the roads just has to be a cat back type modification.