I've been fighting a P0456 error code for the last few weeks. The error started just after we took our R53 in for the power steering pump recall. The dealer swore they hadn't touched anything but the power steering pump, so they felt they weren't responsible for the evac leak error.

I wasn't about to pay them a penny for the repair so I dove into the issue myself.

At first I tried a new gas cap. No luck.

After making my own smoke tester I looked everywhere for a leak. My evac system, however, was tight and no leaks were found.

I swapped out my purge valve with another and still had the error. That's when I realized the issue. I don't want to point fingers without proof but it appears that someone had turned my purge valve upside down!!

As soon as I flipped it over and reconnected the lines my error went away. I put over 300 miles on the car this week and the Check Engine light is still off.

The correct way for the valve to be installed is with the electrical plug towards the bottom.

Hope this helps someone in the future.