OBD-II code · Powertrain (generic)
P019B O2 Sensor Delayed Response - Lean to Rich Bank 1 Sensor 3
Bank 1 sensor 3 O2 sensor reacts only after delay during lean-to-rich transitions. A drifted or sluggish lambda sensor lets the mixture run lean or rich without correction — fuel economy and emissions suffer immediately.
Is it safe to drive with P019B?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySensor aged
Symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
Repair at a glance
- Difficulty
- Easy
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.3–1.5 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Oxygen Sensor B1s3
Related codes
- P013FO2 Sensor Delayed Response - Lean to Rich Bank 1 Sensor 2
- P014BO2 Sensor Delayed Response - Lean to Rich Bank 2 Sensor 2
- P015BO2 Sensor Delayed Response - Lean to Rich Bank 1 Sensor 1
- P015DO2 Sensor Delayed Response - Lean to Rich Bank 2 Sensor 1
- P019DO2 Sensor Delayed Response - Lean to Rich Bank 2 Sensor 3
- P0198Engine Oil Temperature Sensor High
- P0199Engine Oil Temperature Sensor Intermittent
- P019AO2 Sensor Delayed Response - Rich to Lean Bank 1 Sensor 3
- P019CO2 Sensor Delayed Response - Rich to Lean Bank 2 Sensor 3
- P019EAlternative Fuel Tank A Pressure Sensor Circuit
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.