My 2014 volt had error code P1F58 also. I purchased part 22987493 online for $40. I didn't want to pay the dealer $700, so I took on the repair myself. The part is in the back left corner next to the firewall. You can see the part with a flashlight. I took off the plastic engine cover. You just take out the 2 star bolts on the front and disconnect the 2 air hoses on the left and it pulls right out. Next remove the air hose connected to the throttle body. After that remove the throttle body by removing the 4 star bolts and disconnecting the electrical connector by pressing on the tab on the bottom and pulling out. Put a paper towel in the tube the throttle body was connected to. You don't want any junk or parts falling down there. You now have access to the control valve. take off the 2 nuts that bolt the control valve in place. Next you remove the 4 hoses. The top hose and right hose have pins that hold them in place. Pull the pins out (I used a flat head screwdriver and needle nose pliers). Be careful not to lose the pins! After the pins are out pry off the hose using a large flat head screwdriver. The 2 front hoses have clamps. Pinch the clamps and pull them back on the hose past the tube on the valve. I had to pry the hoses off, they have a very tight fit. You lose a little coolant which can be replaced later. Next pull off the electrical connector by pressing the bottom tab and pulling back. The part will now come out. Shove the new part in and connect all the hoses and electrical. make sure to put the pins back in on the top and right hose. Bolt the bracket to the car. Put the throttle body back on and the engine cover. I had to start the car twice before the check engine light would go off. At least that annoying light is off now! This was a painful process because there is so little room to work with. It took me about 3 hours to complete the job.