P013B
O2 Sensor Slow Response - Lean to Rich Bank 1 Sensor 2
Emissions / O2 sensor
Generic OBD-II
Medium
What it means
P013B means the bank 1 sensor 2 (downstream, post-catalyst) oxygen sensor switches from lean to rich more slowly than the ECM expects — usually a sign of an aging sensor. Because this sensor is used mainly to monitor the catalytic converter rather than to control fueling, the engine typically runs normally, but the code should be fixed so the car passes emissions testing.
Medium
Can I keep driving? Safe to drive — this is mainly an emissions-monitoring fault; the engine runs normally, though it may fail an emissions test until repaired.
Common symptoms
What you'll notice
- Check-engine light on
- Often no noticeable change in how the car drives
- Possible slight increase in fuel consumption
- May fail an emissions inspection
Common causes
Most likely first
- Aged or contaminated downstream (post-catalyst) oxygen sensorLikely
- Exhaust leak near the sensor upsetting its readingsCommon
- Wiring or connector fault at the sensorCommon
- Sensor contamination from burning oil or coolantLess often
- Underlying fuel-trim or fuel-pressure issue skewing the mixtureLess often
How to diagnose & fix
Work through it in order
- Scan and read freeze-frame data, and review short/long-term fuel trims.
- Inspect the sensor wiring and connector, and check the exhaust for leaks near the sensor.
- Confirm the upstream sensor and fuel trims are normal first.
- Replace the bank 1 sensor 2 oxygen sensor if it responds slowly, then clear and retest.
FAQ
Quick answers
Is it safe to drive with P013B?+
Yes. Bank 1 sensor 2 is a downstream sensor used mainly for catalyst monitoring, so driving is normal — but the car may not pass an emissions test until it's fixed.
Can I just clear P013B?+
You can, but it returns after a few drive cycles if the sensor is genuinely slow. Replacing the aged sensor is the usual fix.
Related codes
Often seen with P013B
Read & clear P013B yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX