GMC Envoy Vapor Canister Replacement

A while back we were fighting EVAP error codes on the GMC Envoy that we own.  I had replaced the gas cap, the purge solenoid, and the purge valve.  None of these solutions have worked.  Eventually I even took it to the dealer to see if they could solve the issue.  They said that light went off before they got a chance to look at it.  I don’t really believe them since I made sure that the light was on when we took it, but that’s what they said.  I think they cleared the code and tried to replicate it and could not.  That is what was happening to me.  Anyway, they recommended replacing all the fuel vapor lines.  They did this and all was well for a while, but the light came on again.  I eventually figured this out, it was the gas attendant at the gas station that we frequently use.  He was putting the gas cap on crooked and causing the leak.  It always happened after getting gas at this particular station.  So after about $1000 of repair costs (most of that at the dealer) the fix was putting the cap back on after getting gas!

During this fiasco, I had to replace the actual canister.  It was one of the fixes that I found that would possibly cause the error we were getting.  This is how I did it:

I purchased the canister below:

Get out your trusty spare tire lowering tools, these should be located under the seat.  This consists of the lug wrench for the car and the extension to get to the square that will turn to lower the tire.

Put the extension on the square and use the lug wrench to lower the tire.  Remove the tire and put it aside.

Spare Tire Lowering

This will give you access to the actual vapor canister.  It is located almost directly under the filler tube for the gas tank.

Remove the three 1/2” bolts that are holding the canister in.  The vapor canister will kind of slide out if it’s built in holder and be able to be pulled down.  This will allow you to lower the canister and remove the fuel vapor hoses that are going into the canister.

GMC Vapor Canister

Once you get the canister out, take your new one and slide it back into place.  Put the fuel vapor lines back on where they need to be and bolt it back in.

Like I said in the beginning of this post, this did not resolve the EVAP code issue that we were having but it probably needed to be replaced anyway.  The canister that I took out was cracked on the side and was probably helping to cause the issue.  The crack and swelling was from over fuelling the car, you know when you want to get it as full as possible.  This is a not a wise decision in newer cars because the canister will become saturated with fuel and cause issues.  So when the pump clicks, it is recommended that you just pull it out and leave it.

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