GMC Envoy EVAP Issues

My Wife’s been riding around with her check engine light on in her 2007 GMC Envoy for awhile now and I’ve finally been able to get the thing to shut off.  I have been chasing an EVAP system malfunction for about a month and a half.  It’s not for lack of trying but I would get it to go off, it would stay off for awhile and then it would come back on.  I’d fix something else and it would stay off for awhile and then, she would complain about lights being on in her truck and it’s time for a new one.  Since I don’t want a car payment I would go and run the code and find out what the issue is and attempt a repair.  This is the hunt for the EVAP malfunction….

The code that started it all was a P0496 code.  This was for an Evaporative Emissions System High Purge Flow error.  I do a quick code check on my nice new hand held scanner and find that the most likely culprit is a Vapor Canister Vent Solenoid.  So I purchased the part below and replaced it.

 

GMC Code P0496

To do this there are no tools required except for a Jack and a jack stand.

Jack up the driver’s side of the vehicle and place a jack stand on the frame for safety.

GMC Rear Drivers Side Jacked up on stands

The vent solenoid is located next to the fuel tank, towards the top, on the side farthest away from the edge of the vehicle.

Location Of EVAP Purge Solenoid GMC Envoy

Disconnect the electrical connection and the hose that leads to the canister.  Then slide the solenoid off of the metal tab.

All Connections removed

All Connections removed

Reconnect the electrical connector

Reconnect The Electrical Connector

Reconnect The Electrical Connector

Then the hose that leads to the canister.

Reconnect the hose that goes to the vent solenoid.

Reconnect the hose that goes to the vent solenoid.

And slide the solenoid back onto the metal tab.

2007 GMC Envoy New Vent Solenoid

Once all that is complete you can lower the vehicle back onto the ground and hope it resolves that error.  In my case it did but there was more to the story…….

My wife comes home a couple of days later and complains that the truck is beeping at her and showing her a warning that states that the gas cap is faulty and to replace it.

I replace the gas cap.

Another week or so goes by and the check engine light comes back on.  At this point she’s not even telling me because she’s getting used to it, this is why it took a month and a half to get it working!  But I get in the truck on the weekend and sure enough that light is on again!  I pull the code once again and this time it’s different!  At least I’m not getting the same code!  This one is a P0455, Evaporative Emissions System Leak detected (Gross Leak / No Flow).

GMC Envoy P0455 Code

A quick code lookup and it seems that I need to replace the Vapor Canister Purge Valve.

This was an easy one, no tools required at all.

Just locate the part; it is on the driver’s side of the vehicle mounted underneath the intake manifold on the block.

 

This is a picture of the new one installed. But that is where it's located

This is a picture of the new one installed. But that is where it’s located

You will need to remove the 2 hoses that are attached to the Vapor Canister Purge Valve.  One goes up to the throttle body, and the other goes down and back towards the gas tank.  The electrical connector will also need to be disconnected.

You will need to remove the 2 hoses and the electrical connector. Just replace them the same way on the new part.

You will need to remove the 2 hoses and the electrical connector. Just replace them the same way on the new part.

You can then slide the Vapor Canister Purge Valve off of the metal tab and replace it with the new one.

So far there has been no check engine light since the repair and I’ve gotten gas twice!  I think I have finally solved the EVAP system issues.

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