Wheel Related Problems of the 2018 Buick Encore

Wheel problem

8/14-car was lacking power, service manager was able to duplicate issue on road test . 8/24-car service for rough idle and lack of power, service stabilitrak light on and check engine light on with an error code of p0171. In September, car started to shake while in park but no check engine light, dealer advise unable to do any repairs unless check engine light on. 11/27- check engine light on again for same code, p0171. Vehicle is currently in shop. Vehicle has had the same issues Dec 2018 and at the time of purchase. Gm dealers are not able to fix turbo issue and p0171 issues. My vehicle is not operating as designed and it is a safety issue.