P1147 2002 NISSAN ALTIMA SEDAN - Heated Oxygen Sensor 2 Maximum Voltage Monitoring Bank 1
- Faulty heated oxygen (O2) sensor 2 (rear)
- Intake air leaks
- Heated oxygen (O2) sensor 2 (rear) harness is open or shorted
- Heated oxygen (O2) sensor 2 (rear) circuit poor electrical connection
- Inappropriate fuel pressure
- Faulty fuel injectors
Replacing the O2 Sensor 2 usually takes care of the problem
When is the code detected?
The P1147 code is triggered when the maximum voltage from the sensor is not reached to the specified voltage.
- Engine Light ON (or Service Engine Soon Warning Light)
- Possible high fuel consumption
- Possible excessive smoke from exhaust
P1147 2002 Nissan Altima Sedan Description
The Heated Oxygen Sensor
2 (HO2S) (Rear O2 Sensor), after three way catalyst (manifold), monitors the oxygen level in the exhaust gas on each bank
. For optimum catalyst operation, the air fuel mixture (air-fuel ratio) must be maintained near the ideal stoichiometric ratio. The HO2S output voltage changes suddenly in the vicinity of the stoichiometric ratio. The Engine Control Module (ECM
) adjusts the fuel injection time so that the air-fuel ratio is nearly stoichiometric. The HO2S generates a voltage between 0.1 and 0.9 V in response to oxygen in the exhaust gas. If the oxygen in the exhaust gas increases, the air-fuel ratio becomes Lean. The ECM
interprets Lean when the HO2S voltage is below 0.45 V. If the oxygen in the exhaust gas decreases, the air-fuel ratio becomes Rich. The ECM
interprets Rich when the HO2S voltage is above 0.45 V.