You need to solve the car engine when any problem is detected in the car engine. The car engine P1451 Code is found when the car engine is tested. The real meaning of the code is necessary to know the real cause of the car engine problem but automobile dictionary meaning of the code supports to solve the car engine. The automobile dictionary meaning of the code is p for Powertrain Code Problem is related engine, transmission and emissions systems. 1 for MFG – Manufacturer Specific. 4 for Transmission. 5 for TP Sensor Learn Not Complete and 1 for TFP Valve Position Switch-Drive Without Drive Ratio.