One problem related to check engine light on has been reported for the 2006 Nissan Titan. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2006 Nissan Titan based on all problems reported for the 2006 Titan.
I think it was in 2009 when I took my vehicle to Nissan to check engine light and light smoke out of exhaust. Ran diagnostic and found out that catalytic converters broke up and broken material went back (suckback) into engine and damaged piston rings which was causing it to smoke. Told me I needed to replace engine cause it was pretty much no good. This truck was 3 yrs. Old at the time. Warranty was out and was and cost me a fortune to replace engine and exhaust system. I had no idea til now how many 2006 Titan owners have had the same issue. This has to be recalled.