Just got back from having my 2004 Nissan Titan Inspected, and it failed due to Evaporative Emission Control System Leak Detected (gross leak). What would cause this?
Well, I thought most EECS were designed to trap vapors from the gas tank inside some sort of charcoal based canister. Maybe replacing the canister would do the trick as the existing one might be saturated. I suppose you could also have a leak somewhere in tubing or conduit connecting the tank to the system. I believe there is also a purge valve that can go bad.
If there is a gross leak, then my guess is some tubing is disconnected or has holes in it so that vapor isn't getting to the canister properly. It is probably easier and cheaper to just replace the tubing first and see if that does the trick.
As stated above, assuming you have less than 100k, the dealer should take care of this issue.
the emissions are not covered by a 100k warranty. and only some emissions items are covered by the federal mandated 8yr-80k mile warranty, most notably ECM and catalysts. the gross leak could be caused by a broken hose, faulty vent valve, broken canister, loose/poor sealing fuel filler cap, etc...