2000 blazer stuck in auto 4wd

2000 Chevy Blazer, bought it recently the service 4wd light was on when it was in 2hi, put it in auto 4wd during a snow storm and now it will not go back into 2hi, doesnt blink or anything. Also if im backing up and turning or pulling into a parking spot and the wheel is turned a decent amount its like my engine is stumbling and wants to shut off until i straighten the wheel out again. what could this be?

It sounds like you have a vaccum leak somewhere. There are many more possibilities, but maybe check your vaccum lines to start.

Is the check engine light on also?

no check engine light just the service 4wd