A very common problem with Nissan vehicles. Before replacing any parts, check for damage EVAP canister and for loose hoses from the vent control valve to the canister.
There is a factory Nissan service bulletin to help diagnose the P0448 code:
Nissan Factory Service Bulletin OBDII Code P0448
There are factory service bulletins for the following Nissan models:
2005-2007 Nissan Pathfinder
2005-2007 Nissan Pathfinder Service Bulletin OBDII Code P0448
2007-2009 Nissan Altima Sedan
2008-2009 Nissan Altima Coupe
2007-2009 Nissan Altima Hybrid
2009 Nissan Maxima
Nissan Factory Service Bulletin OBDII Code P0448
2006-2015 Nissan Titan
2006-2015 Nissan Titan Factory Service Bulletin OBDII Code P0448
Check the 'Possible Causes' listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.
The cost to diagnose the P0448 Nissan code is 1.0 hour of labor. The diagnosis time and labor rates at auto repair shops vary depending on the location, make and model of the vehicle, and even the engine type. Most auto repair shops charge between $75 and $150 per hour.
EVAP canister vent control valve remains closed under specified driving conditions.
Need more information on how to fix the P0448 Nissan code? Get Access to Factory Service Manuals
Get the P0448 Nissan code diagnosed by a professional: Find a repair shop in your area