Nissan P1273-Air/Fuel Ratio Sensor Lean Shift Monitoring

Nissan P1273 Air/Fuel Ratio Sensor Lean Shift Monitoring Sensor 1 Bank 1

Code P1273 Nissan is DTC code relating to air and fuel metering. When vehicle computer detect a problem with fuel system pressure or flow rate code p1273 is stored in engine control module (ECM)

Fault Location-Fuel pressure system

Possible Causes Code P1273 Nissan

1.When fuel pump is not functioning properly or fuel pump is failing it causes engine to run lean triggering p1273.

2.Faulty fuel pressure regulator result in incorrect fuel pressure which can cause engine to run lean triggering this code.

3.Clogged fuel filter can can restrict free fuel flow to the engine causing engine to run lean and trigger p1273.

4.If fuel pressure sensor is not functioning correctly it sends incorrect signal to ECM causing engine to run lean and trigger this code.

5.Vacuum leak in the intake manifold can cause engine to take too much air and run lean triggering p1273.

6.Issue with the wiring in the fuel system can cause incorrect signals to be sent to ECM causing engine to run lean and trigger this code.

7.In come cases failed engine control module (ECM) may be cause of p1273.

Nissan P1273 DTC Code Possible Symptoms

1.Reduce engine performance, engine may run poor or lack power.

2.Engine may misfire or run rough.

3.Decreased fuel efficiency in the vehicle when p1273 is present.

4.The vehicle may stall or experience starting difficulties.

5.Engine check light or warning light may illuminate.

How To Fix Code P1237 Nissan

1.Visually inspect fuel pump, fuel filter, fuel pressure regulator and fuel pressure sensor for any issues.

2.Perform fuel pressure test to find out that fuel system is functioning within the vehicle manufacturer specification.

3.Inspect intake manifold for vacuum leak, if found repair it to prevent the engine from running lean.

4.If any component found faulty during inspection such as faulty fuel pressure regulator, clogged fuel filter or failing fuel pump replaced it.

5.If any wiring issue is found, wiring need to be repaired or replace to ensure correct signals are being sent to ECM.

6.If ECM found faulty replaced ECM.


Its important to have the vehicle inspected and diagnosed by professional mechanic to find and resolve issue related with code p1273 Nissan for proper repair.

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