Chevy Trailblazer rack-and-pinion problems

I presume it has been converted from left-hand drive to right, so I would be going back to the people who did the conversion, as it would appear there could be a problem related to the conversion. You need to start by finding out what components were used in the conversion, the steering rack being one of them. The next step would be to find a competent mechanic to fix it.