96 4Runner Limited Won't Move

The car starts fine, gasses fine but when I move it into drive the vehicle will not move and there is "A/T P" next to the fuel gauge. When I put it back into park it makes a loud sound (metallic almost).

This happens when the 4wd button is out and 4wd is in Normal. If I move it to H or L4 the vehicle will move.

Also, I just checked and the dashboard now has the 4wd light in green (it look like an H )

Check the condition of your transmission fluid and the level (while engine is idling on level surface after run through the gears). If may be low or very dirty - first add fluid if low and try it. Then pull the transmsission pan and check the magnets for filings. If there are chunks of metal on the magnets, it's time to give up on cheap fixes.

If there is no hint of metal chunks on the magnets, before you do expensive work, try flushing the transmission and replacing the gear oil in the transfer case. It is a relatively cheap try. You may still need expensive work, but unless you have a Check Engine light on and it indicates a transmission code, there is no easy way. The dealer may be able to diagnose this better with a tester.