2023 Z51 with 1,300 miles threw code P12F0 - Cylinder Deactivation Exhaust Flow Valve Stuck Open-Bank 1. Dealer attempted to re-learn AFM actuator multiple times with no success and recommends replacement, but the part (#84896575) is nowhere to be found, now on special order with no ETA. Dealer says actuator is sluggish and doesn't open the valve fully (don't understand how they know that without dropping the exhaust...does anyone here know?). My concern is that without dropping the exhaust it might be a combination of the actuator, the linkage to the valve, or the valve itself. The linkage could be binding and need a little adjustment. If the valve is bad, I don't know if the valve is replaceable within the exhaust system...does anyone here know? I've looked at the exploded view, but can't figure it out. Could need more unavailable parts after torn apart to replace actuator. Dealer says it's OK to drive. It threw same code right after leaving. Do you guys agree? I would really appreciate any feedback on my situation. Many thanks in advance.