The deactivation method of cylinders is realized by discharging a synchronizer pin that is usually interlocks with the cam follower and rocker arms. The car engine P2161 code solves the synchronizer pin of the car engine is released using hydraulic compression which is measured by a dedicated solenoid. The car engine P2161 Code convey many information and learn about the car engine problem for solving the car engine. Do not try to solve the car engine by any wrong meaning of the code what may create serious problem in the car engine. You should depend on the automobile engineer who knows well how to fix the car engine.