Subaru EVAP valve replacement

 "Your happiness depends on three things, all of which are within your power:  Your will, your ideas concerning the events in which you are involved, and the use you make of your ideas." - Epictetus

Earlier I posted about the Subaru's "Check Engine" light and doing a bit of troubleshooting.  I replaced the gas cap and reset the check engine light, because that was an easy and cheap fix for what might have been the problem.  The light came right back on a day later.  Same after I smoke-tested the system.

At that point I decided to replace the two solenoid valves that work together to operate the system, since it appeared that there were no air leaks.

Below:  Ready to begin.  Take a deep breath, prepare to get dirty and have some skinned knuckles.

The gas tank vent valve was the "easier" of the two solenoid valves to replace, from an access perspective.  All I had to do was lift the car up and partially remove the charcoal canister to get to the valve.  Oh, and have rust and dirt particles raining down on my face the entire time :).

Below:  The charcoal canister is the black rectangular box dead center.  The vent valve sits above and outboard of it.  Enough so that the canister interferes with removing the valve.

Below:  The vent valve that I wanted to replace.  The bolt that holds it in place is hidden by the canister.

Below:  Replacement valve halfway installed, canister still loose.

Below:  The old gas tank vent valve on the bench.  When I put power to it, the valve closed and sealed well when I tried to blow through it.  When de-energized, it opened properly.  Seems to be fine.

With that valve replaced and the canister back in position, I took the car off the jack and started in on the difficult valve - the EVAP purge solenoid valve.  This is the one that puts your gas tank under a very slight vacuum whenever the engine is running, and helps the engine recover vapor from the canister, so once the engine is shut down, the canister is fresh to absorb gas vapor again once the vent valve opens.

Below:  The EVAP purge solenoid valve is absolutely buried on this car.  It's under the aluminum intake manifold runner, but you can't even see it from the front of the engine.

Below:  View from the rear of the engine, looking toward the front of the car, you can just see the solenoid and electrical connector to the EVAP purge solenoid valve.

Below:  Same image with arrows, showing the EVAP purge solenoid valve body on the left, electrical connector on the right.  The fastener bolt cannot be seen.  You have to feel for it.

There was a lot of interference to remove in order to get access to the bolt that holds the valve in place.  It screws into a piece of webbed aluminum under the intake manifold.  I have no idea why they put it there, of all places.  The clean air intake had to come off, as well as the smaller hoses attached to it.

Below:  After a brief battle with a mounting bolt that could only be felt, I got the new EVAP purge solenoid valve installed.  None of the interference has been re-connected in this image, and the electrical connection is still loose.  I was just happy to get the new valve mounted at this point.

And below:  The old EVAP purge solenoid valve on the bench.  This also appears to function properly.  When de-energized, you cannot blow through it.  When energized, you can blow through it. 

It's possible that one of these old valves was only opening or closing intermittently.  I reset the check engine light and we will just have to wait for a hot day and see if the issue is gone or not.  I have taken the car out for a test drive and made one commute to work and back, with no issue so far.  Updates will follow if there is an issue after this repair!

Update 9-30-22:

The check engine light is back.  I'll have to try the smoke tester again.