Steering issue sounds like air in your PS system that needs to be bled out. Did you authorize any power steering service?
A GM dealership did this?
As far as the rough idle goes, you'd need to disclose your specific engine for an accurate guess on what's wrong as plug replacement procedures are different between DI & non-DI engines.
You mentioned in another thread that your battery was (poorly) replaced. It's possible that the throttle re-learn procedure outlined in your owners manual wasn't performed after replacement.
Either way, sounds like they did a bang up job on your car. Maybe the mechanic called in sick and the detail kid was slow on work.
A GM dealership did this?
As far as the rough idle goes, you'd need to disclose your specific engine for an accurate guess on what's wrong as plug replacement procedures are different between DI & non-DI engines.
You mentioned in another thread that your battery was (poorly) replaced. It's possible that the throttle re-learn procedure outlined in your owners manual wasn't performed after replacement.
Either way, sounds like they did a bang up job on your car. Maybe the mechanic called in sick and the detail kid was slow on work.