:evil: Suzuki GURUS help me please

[PaulyBoy23]

16 valve,Automatic, a couple issues that are bugging the heck out of me.

1. If I put it in neutral and give it a slight rev it goes up then down then stalls and if it doesnt stall i rattles and shakes like its going to, Its terrible I went to the cut out for a fish as soon as the sand got a lil soft couldnt move in low or second month or so ago wouldnt worrie her in the slightest its like all my low down grunt is going the revs will come right down after and try to stall?

2. After 4wd and going to put back to 2wd my car revs like its in neutral nothing in 2wd works put it in 4wd of she goes 2 mins later 2wds good again

Please help this is driving me nuts