P013C
O2 Sensor Slow Response - Rich to Lean Bank 2 Sensor 2
Fuel & air metering / emissions
Generic OBD-II
Medium
What it means
P013C means the downstream (post-catalyst) oxygen sensor on bank 2 is switching from rich to lean too slowly. This sensor mainly monitors the catalytic converter, so the car usually drives normally, but a lazy sensor sets the light and can cause an emissions-test failure. Aging sensors and small exhaust leaks are the common causes.
Medium
Can I keep driving? Safe to drive — this is a downstream oxygen-sensor response fault; the car runs normally but may fail an emissions test until it's fixed.
Common symptoms
What you'll notice
- Check-engine light on
- Often no noticeable change in how the car drives
- May fail an emissions/readiness test
- Slightly higher fuel consumption in some cases
Common causes
Most likely first
- Aged or contaminated downstream oxygen sensor (bank 2, sensor 2)Likely
- Exhaust leak near the rear O2 sensor letting outside air inCommon
- Corroded or loose sensor connectorCommon
- Contamination from oil or coolant burning in the exhaustLess often
- Rarely, an ECM/PCM faultLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and check for exhaust leaks upstream of the rear sensor.
- Inspect the bank 2 sensor 2 connector and wiring for corrosion or damage.
- Compare the sensor's switching speed in live data against the front sensor's.
- Replace the downstream oxygen sensor if it's slow and the exhaust is sealed — the usual fix.
- Clear the code and drive a full cycle to confirm it stays off.
FAQ
Quick answers
Is it safe to drive with P013C?+
Yes. The rear oxygen sensor mainly monitors the catalytic converter, so the car drives normally. The main consequence is failing an emissions test until it's repaired.
Can I just clear P013C?+
You can, but it returns once the monitor runs again if the sensor is truly slow. Confirm there's no exhaust leak, then replace the sensor if needed.
Related codes
Often seen with P013C
Read & clear P013C 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