First off, you may be able to disconnect the battery cables (both) for 5-10 minutes and clear the system. Then drive it normally and after a certain amount of time, it will relearn itself, driving parameters etc (sometimes a few days, sometimes longer or shorter). If the fault is still present, the code will set again. If it isn't present anymore, then no need to worry anymore. I always take note of a code then reset the system and see if it reappears. On occasion codes will set and do not return after resetting the system. Not often, but worth trying that first to verify there really is an ongoing issue. If it does present itself again, look at this link. Maybe it will help. http://www.justanswer.com/questions/10nxy-fix-trouble-code-p0446
Trouble code P0446 means: EVAP Vent System Performance
Trouble code P0446 means: Evaporative Emission System Vent Control Circuit
Trouble code P0446 means: Evaporative Emission System Vent Control Circuit
Trouble code P0446 means: Evaporative Emission System Vent Control Circuit
Trouble code P0446 means:Evaporative emission control system vent control circuit malfunction
Trouble code P0446 means: EVAP Vent System Performance
Trouble code P0446 means:Evaporative emission control system vent control circuit malfunction
Trouble code P0446 means: EVAP Vent System Performance
The car code p0446 is a faulty vent valve. To fix this problem, the vent valve will need to be replaced.
Trouble code P0446 means: Evaporative Emission System Vent Control Circuit
Trouble code P0446 means: Evaporative Emission System Vent Control Circuit
Trouble code P0446 means: EVAP Vent System Performance