One problem related to auxillary tank has been reported for the 2004 Nissan Titan. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 Nissan Titan based on all problems reported for the 2004 Titan.
When pumping gas the gas from the tank projects back at the person putting fuel into the tank. Owner took the vehicle back to the dealer, where it was determined to replace the tank.