The car engine P2168 Code lets us know about the car engine problem. The general meaning of the code helps to fix the car engine but the right meaning of the code is the first choice for solving the car engine. When the car engine code’s real meaning is not found, then you must look for alternation and that can be general meaning of the code. The automobile/general meaning of the code is p for Powertrain Code Problem is related engine, transmission and emissions systems. 2 for MFG – Manufacturer Specific. 1 for Transmission. 6 for Control Module Throttle Actuator Position Performance and 8 for PCM Stack Overrun.