P0153 2/1 O2 Sensor Slow Response
NAME OF CODEO2 Sensor Slow Response
WHEN MONITORED
With the engine temperature greater than 147°F, after reaching a vehicle speed of 10 mph, and the throttle remaining open (off idle) for two minutes, bring the vehicle to a stop and allow the engine to idle with the transmission in drive (auto) or in neutral (manual).
SET CONDITION
The oxygen sensor signal voltage is switching from below 0.27 volts to above 0.62 volts and back fewer times than required.
THEORY OF OPERATION
Effective control of exhaust emission is achieved by an oxygen feedback system, of which the most important element is the oxygen sensor (O2S), which is located in the exhaust paths. Once the sensor reaches its normal operating temperature of 300°-350°C (572-662°F), it generates a voltage inversely proportional to the amount of oxygen in the exhaust. Response rate is the time required for the sensor to detect changes in the exhaust gas oxygen content; it switches from lean to rich if it is exposed to a higher than optimum A/F mixture, or vice versa. The O2S output voltage ranges from 0 to 1 volt. A good sensor easily generates an output voltage in this range as it is exposed to different oxygen concentrations. To detect a shift in the A/F mixture (lean or rich), the output voltage has to change beyond a threshold value. A malfunctioning sensor could have difficulty changing beyond the thresholds.
POSSIBLE CAUSES
- Exhaust lean
- Fuel contamination
- O2 sensor failure
- Electrical wiring connectors
- O2 heater failure
NOTE: The above calibrations are approximate values.