when making a sharp turn a low speeds the engine loses rpm and almost dies on 2002 GMC Envoy

this has just started it feels as if the rear drive wants to go but the front end is locking up. i do not hear any grinding or smell any stong odors at this point does not seem to happen in reverse

Asked by for the 2002 GMC Envoy
4x4 system is actve! What you feel is common on dry pavement with four wheel drive activated. All 4x4 vehicles do this! Now why it is in four wheel, well that i can't tell you.