Goes off as I turn corner

Whoever said it needs a tune up to repair a shutdown situation isn't paying attention and won't be able to fix it that way. I don't know what a 'crossover' is, so no comment there. The power steering is a separate issue. Power steering repairs' cost depends on what is failing. You may need a major service and brake job but that all won't help the shutdown problem. Sounds like an electrical problem if the entire system shuts down. Fix it ASAP, it's a safety issue. You need to find a Kia specialist and forget whoever you've been going to. Here's a directory link for you: https://repairpal.com/kia-repair-in-glen-burnie-maryland