When DTC code P0053 OBDII is set, it is because the Powertrain Control Module (PCM) has observed that the electrical resistance of the Oxygen Sensor (O2) control circuit number 1 in bank 1 is outside the default parameter.
The resistance in this circuit is usually 8 ohms or close to 8 ohms. Note that the resistance value varies by manufacturer. If there is a difference of at least 10% of this value, this code is established.
Because the exhaust stream content changes continuously during normal engine operation, the O2 sensor uses the variable oxygen content of the exhaust gas to produce signal voltages, which are used by the PCM to control changes in fuel supply, ignition time, and timing of the VVT (Variable Valve Timing) system valves. When the oxygen sensor is working properly, it reacts to changes in oxygen content quickly, ensuring that the PCM can manage the engine efficiently.