The engine P2801 Code helps you to know the problem of the car engine. Like the car engines, the engine system services especially advanced hydraulic lifters which is known as switching roller followers for the engine P2801 code ingestion and exhaust regulators. The lifters can be distorted by disengaging an inner locking pin. The locking pin is disconnected using solenoids to change oil compression fed into the lifter. You can use automobile dictionary meaning of the code is p for Powertrain Code Problem is related engine, transmission and emissions systems. 2 for MFG – Manufacturer Specific. 8 for Ignition System Or Misfire. 0 for IC Circuit High Voltage and 1 for TFP Valve Position Switch-Drive Without Drive Ratio.