Powertrain
generic / SAE
P015C
O2 Sensor Delayed Response - Rich to Lean Bank 2 Sensor 1
Pre-cat O2 sensor on bank 2 reacts only after delay when mixture switches rich to lean. A drifted or sluggish lambda sensor lets the mixture run lean or rich without correction — fuel economy and emissions suffer immediately.
SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number1 / 5C
Possible causes
- Sensor aged high
Symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
Inspection / repair
- Difficulty: easy
- DIY: possible
- Estimated cost: 60–300 €
- Estimated time: 0.3–1.5 h
- Component: oxygen sensor b2s1
- MIL / check engine light
- emissions-relevant
- drive cycle required
Sources
References
sae:J2012