2008 Chevrolet Impala LT 3.9L stalled with DTC P0016. Towed home and replaced camshaft position sensor and crankshaft position sensor and inspected connecting wires. Also checked that camshaft actuator solenoid operation by pulling and applying power and checked that the actuator on the camshaft returned to position when pressed in. Also disconnected the battery for 8-12h, reset codes, and tested that I have spark.
Timing seems way off. When I have someone try to start it with my hands over the exhaust pipes I feel suction, and can hear air being pushed out the throttle body.
Did the timing chain break or skip? Is there a way to tell without tearing the front end off?