Should you drive your 1999 Toyota 4 runner in 2h 4h 4l?

Not that you have any other options but the answer is yes you should.

So given the fact you knew that I ask what it is you are really asking?

2H for all driving conditions that you dont need extra traction or pulling power. 4H is if you need extra traction on slippery, wet, sandy or mountainous areas. 4L if you are pulling a heavy load, need to go slow in sandy, slippery, wet snow or going slow up a steep hill. 4L is for lower than 40 mph speeds.

Hope this helped.