P1273 NISSAN - AIR FUEL RATIO SENSOR SENSOR 1 BANK 1 LEAN MIXTURE
POST UPDATED IN June, 2023
P1273 NISSAN - AIR FUEL RATIO SENSOR SENSOR 1 BANK 1 LEAN MIXTURE
The Air/fuel ratio sensors measure the oxygen in the exhaust gas. Unlike the oxygen sensors that have a signal variation between 0.9 and 0.3V, depending on whether the mixture is lean or rich, the air/fuel ratio sensors give the exact oxygen content to the exhaust stream. Then, they generate a signal that matches exactly that value.
The Air Fuel Ratio Sensor makes the signal current flows in two directions, which are positive and negative. The PCM (Powertrain Control Module) supplies these sensors with 2.6 volts of reference. In some cases, it supplies 3.3V, which works as a power source. As the air/fuel mixture changes during normal engine operation, the signal voltage sent tends to shift to the positive direction if the mixture is lean. When the mixture is richer, it shifts in the negative direction.
However, when the sensor is working properly and the engine or exhaust system is not faulty, current flow is completely stopped as long as the exhaust gas composition is “stoichiometric”. This means that all of the fuel being burned uses all of the available air in the air/fuel mixture. If the PCM detects a lean operating condition or too much air in the mixture, the P1273 OBDII diagnostic code will be set.
Reasons for setting the P1273 OBD2 DTC code on a Nissan vehicle:
Steps to solve the P1273 OBDII fault code on Nissan vehicles: