[HUMTECH]

Sounds like you may have 2 possible problems. Def airbag rot if at extended height the system loses pressure quicker than when at trim height, as stated above bags tend to dry rot and crack at the bottom, when they are extended the leak gets worse. I would address that first. If left sensor code continues to set, id bet dollars to doughnuts left ride height sensor is bad. I have had to diagnose over 100 ride height sensor problems, left side is 99 Percent of the time the sensor. Right side always is the harness has a break in a wire, almost always. Not sure why but that is what i have always found