Hard steering 2006 dts Cadillac ( left easy right hard )

That particular car has computerize steering so you can not oversteer on the freeway at high speeds, if my memory serves me correctly there was a recall on that particular vehicle, check with the Cadillac service manager at your local dealer and tell me what they say

Faulty power steering gear(rack/pinion). The magnasteer system is an electro-mechanical function of the steering gear to increase effort at higher speeds. It has nothing to do with specifics of either right or left. There is no recall for this concern.