evap purge/vent solenoid condition. anyone have any experience with this? this is on my moms yukon,the mileage has dropped from 18 to 13 according to the computer. any help will be appreciated

 

Could be a bad purge valve, or one of the hoses aren't connected...trying to think how it would affect fuel economy though. Maybe if the valve was stuck upen and constantly purging it would throw off the a/f ratio causing the pcm to make negative adjustments?

 

couldnt tell you, i have noticed a stumble at idle, and hesitation at part throttle. 51k on this vehicle.

 

Check and make sure that all of the hoses to the evap system are hooked up, a hose may be dis-connected or may have a hole in it. If the hoses are intact, my guess would be a bad purge valve...I can't remember where it's located though