2003 Nissan Maximarecently I changed the evap purge control valve solenoid and #5 cyl (misfiring)now i am getting a p1800 code i have checked the air intake solenoid and it is fine what else can cause that code. Could the evap canister vent be stuck open ? It is kinda making a whirly bird sound now and when it gets hot it just looses power and shuts down.