Exhaust Catalytic Converter For NISSAN ARMADA 5.6L 2005-2015 Rear Bank 1 &Bank 2Catalytic Converter For Nissan Titan 5. 6L 2004 2015 Specification? Catalytic converters can be damaged by road debris, contaminated by engine oil or coolant, or become clogged and restrict exhaust flow. It's time to replace your catalytic converter when comes to the following symptoms Among the symptoms of a bad catalytic converter are: Sluggish engine performance Reduced acceleration Dark exhaust smoke The smell of sulfur or rotten eggs from the