Hello -- 06 Ram 2500 4x4; 285k miles
I'm considering removing my catalytic convrtr. Two questions:
1) Is the cat necessary? (I'm not asking for an EPA or legal opinion.)
2) Should I also remove the muffler? (I intend to leave the muffler in leave and simply cut out the cat asked replace the gap with a straight pipe tube. But should I leave the muffler or remove it also?)

Thanks! D

 

My buddy has an '06 and removed the cat and muffler about a decade ago.

Watch out for inspections and your laws. In my area, a vehicle inspection includes making sure the emissions equipment is still intact. OTOH, there is generally no requirement for inspection unless the vehicle is coming from outside the province, or a cop has ordered you to have one.

 

Unless you have a gasser, it is a diesel particulate filter (DPF). People remove them or bore them out either because they get clogged and are expensive to replace or "cook out", but mostly they want a less restrictive exhaust.

Why and how to modify it would depend on if you could get away with it. In the states, getting caught with disabled/removed emission equipment can result in big fines.