I'll add my tale of H6's not liking to be run for 20 seconds then parked then started the next day...

Had to move my car to get the wife's forester in the garage yesterday, was only about 30 degrees. Moved it 30 feet, ran it 20 seconds or so, was interested to see what the next day's start would be like. Contemplated taking around the block just in case. Should have!

Well, the car had so little compression the next day I was not even sure it was turning over! Holy crap!

It was not flooded as far as I can tell, just seemingly had zilch for compression.
But for opening the car door I would have sworn the starter was spinning but the engine not turning over.

Took quite a bit of cranking before it even seemed like it was going to kick.
Cranking with it floored did bupkis.

Started and ran normally after many attempts.


Oh, and add me to the P0420 club, too, got the code a few times before this fun...

More than likely the plugs were fouled. That makes it a bintz to start, especially when they get wet with that cold start fuel mixture.

 

Best thing is to avoid those quick start, move, shut off scenarios. If you have to start into move it, especially in cold weather, let it run for a few minutes before shutting it off.