P1146 2002 NISSAN ALTIMA SEDAN Possible Causes
- Faulty Heated Oxygen Sensor (O2) 2 (rear)
- Intake air leaks
- Heated Oxygen Sensor (O2) 2 (rear) harness is open or shorted
- Poor electrical connection in the Heated Oxygen Sensor (O2) 2 (rear) circuit
- Inappropriate fuel pressure
- Faulty fuel injectors
How to Fix Code P1146 2002 NISSAN ALTIMA SEDAN?
Start by checking the “possible causes” listed above. Visually inspect the corresponding wiring harness and connectors. Look for damaged components and check for broken, bent, pushed out, or corroded connector pins.
Technical Notes
Replacing O2 sensor 2 usually resolves the issue
Possible Symptoms
- Engine Light On (or Service Engine Soon Warning Light)
- High fuel consumption
- Excessive smoke from exhaust
P1146 2002 NISSAN ALTIMA SEDAN Meaning
The Heated Oxygen Sensor 2 (HO2S) (rear O2 sensor), located after the three-way catalyst (manifold), monitors the oxygen level in the exhaust gases on each bank. For optimal catalyst operation, the air-fuel mixture (air-fuel ratio) must be maintained close to the ideal stoichiometric ratio. The HO2S output voltage changes abruptly near 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 the oxygen in the exhaust gases. If the oxygen in the exhaust gases 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 gases decreases, the air-fuel ratio becomes rich. The ECM interprets Rich when the HO2S voltage is above 0.45 V.