P0139

Tests 1 - 4:

Tests 5 - 6:

SYMPTOM
P0139-1/2 O2 SENSOR SLOW RESPONSE

TEST NOTE
This symptom is diagnosed using the test P0133-1/1 O2 SENSOR SLOW RESPONSE.

WHEN MONITORED
Start engine. Allow engine to idle. For 1st part of test, if limits are exceeded, test passes. If not, 2nd part of test runs. amb/batt temp > 44 °F, Baro > 22.13" H2O, battery > 10.5 volts, MAP > 11.79 & < 18.15" H2O, RPM > 1350 & < 2200 and VSS > 50 and < 65.

SET CONDITION
The oxygen sensor signal voltage is switching from below 0.39 of a volt to above 0.58 of a volt and back fewer times than required.

POSSIBLE CAUSES
- Intermittent condition
- Exhaust leak
- O2 Sensor signal circuit voltage drop
- O2 Sensor ground circuit voltage drop
- O2 Sensor