P1273 2004 NISSAN MAXIMA - Air Fuel Ratio Sensor 1 Bank 1 Lean Shift Monitoring
Possible causes
- Faulty Air fuel ratio (A/F) Sensor 1 Bank 1
- Air fuel ratio (A/F) Sensor 1 Bank 1 harness is open or shorted
- Air fuel ratio (A/F) Sensor 1 Bank 1 circuit poor electrical connection
- Fuel pressure
- Faulty Fuel injector
- Faulty Air Flow Meter
Tech notes
Maxima ECM Self-Learning procedure
Nissan Service Bulletin OBDII Code P1273
There are factory service bulletins for the following Nissan models:
2004 Maxima (A34) with 5 speed A/T only
Nissan Factory Service Bulletin OBDII Code P1273
2004 Maxima (A34) with 4-speed A/T and 6-speed M/T
Nissan Factory Service Bulletin OBDII Code P1273
When is the code detected?
Possible symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
- Possible rough engine idle
P1273 2004 NISSAN MAXIMA Description
The sensor is capable of precise measurement λ= 1, but also in the lean and rich range. Together with its control electronics, the sensor outputs a clear, continuous signal throughout a wide λ range (0.7 < λ < air).
The exhaust gas components diffuse through the diffusion gap at the electrode of the oxygen pump and Nernst concentration cell, where they are brought to thermodynamic balance.
An electronic circuit controls the pump current through the oxygen-pump cell so that the composition of the exhaust gas in the diffusion gap remains constant at λ = 1. Therefore, the A/F sensor is able to indicate air/fuel ratio by this pumping of current. In addition, a heater is integrated in the sensor to ensure the required operating temperature of 700 - 800 C (1,292 - 1,472 F).

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P1273 2004 NISSAN MAXIMA Comments
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