I have a 2012 GMC Sierra with 5.3 Vortec. I had to replace one head due to damaged exhaust valve. Completed the work and truck is running but on reduced power. Code reader shows 3425-3441-3401-3449 which are the solenoid deactivation codes for the 4 AFM cylinders. I assume I have done something or missed something that is causing this to all 4 of these cylinders. Any suggestions on what steps to take to resolve? Visual inspection of wiring and vacuum hoses has found nothing. Oil was change with Mobil 1 and new filter. Possoibly in limp mode but these are only codes showing.