2005 Yukon XL 5.3 Code P0496

[mountie]

P0496..... my little code checker displayed this, also.....
EVAP system " High Purge Flow "..... Looking online, it is on my intake... Is the tube, connected, run to my rear fuel vent system? Maybe that's a partial cause, when I fuel up, the gas shuts off at the gun? Is that the tube I might try to blow out filter material?
I'm getting a new purge valve and replace it. ( Fortunately, it is easy to get to )

 

[Big Mama]

How’s your gas cap?

 

[Fless]

The evap purge line goes down to the charcoal canister. If you go to blow out that line, first disconnect it at the canister. That will help you determine if any charcoal bits were in the line, and will give you a chance to inspect the canister for loose charcoal.

The purge valve itself can be tested by removing it and attempting to blow through it. Apply 12vDC to the terminals and it should open; with no voltage applied it should be sealed. They can be intermittent so if you test like this be sure to cycle it multiple times. And be sure the o-ring on the bottom of the valve is in good condition.

 

[mountie]

How’s your gas cap?

New...... the warning use to show " tighten gas cap"... But that was just a symptom.... Not the reason

 

[mountie]

The evap purge line goes down to the charcoal canister. If you go to blow out that line, first disconnect it at the canister. That will help you determine if any charcoal bits were in the line, and will give you a chance to inspect the canister for loose charcoal.

The purge valve itself can be tested by removing it and attempting to blow through it. Apply 12vDC to the terminals and it should open; with no voltage applied it should be sealed. They can be intermittent so if you test like this be sure to cycle it multiple times. And be sure the o-ring on the bottom of the valve is in good condition.

I read that description..... Plus... The purge valve, does not effect the gas pump- filling problem... When the truck is turned off, that valve is closed... I suppose....

 

[Fless]

I read that description..... Plus... The purge valve, does not effect the gas pump- filling problem... When the truck is turned off, that valve is closed... I suppose....

If it's defective and remains open with the ignition off, it may allow fuel vapors into the intake and create a hard start condition (flooding).

When you change that purge valve I think there's a small rubber "mount" or piece under where it mounts (different from the o-ring); the new one may not come with one so move it over to the new one.

 

[Big Mama]

If I remember right I changed my gas cap after getting the message about it being loose, which didn’t fix it, so I bought the purge canister kit, including hoses, and that fixed it.

 

[mountie]

Just replaced the Purge Valve....
#1 Notice the charcoal bits stuck inside the OLD canister tube-intake..Should I blow out the tube, after disconnectthe other end, from the rear canister??
#2 The green cap covering the valve opening..
#3 The valve inside the green cap.... A "tire style valve" ? Huh? Anyone change that?? ( Leave it alone?? )

Anyway, maybe filling the tank might be better..... I hope....

 

[mountie]

New purge valve replaced..... Wow... It's like my Yukon "woke up" ... It leaves a stop sign so much smoother and ... performs better !! An amazing improvement after spending less than $50.

 

[89Suburban]

Did you blow the lines out?