P046B
Catalyst Temperature Sensor 1/2 Correlation Bank 2
Catalyst / emissions
Generic OBD-II
Medium
What it means
P046B sets when the two catalyst temperature sensors on bank 2 report readings that don't agree with each other the way the ECM expects. It's a sensor-correlation code, so it's almost always a failing temperature sensor, drift, or a wiring fault rather than a problem with how the car runs — but it will keep the catalyst monitor from completing.
Medium
Can I keep driving? Drivable — this is a monitoring fault with no immediate driving risk, but the catalyst monitor won't be ready and the car will fail an emissions test.
Common symptoms
What you'll notice
- Check-engine light on
- No noticeable change in how the car drives
- Catalyst readiness monitor not completing
- Failed emissions / smog test
Common causes
Most likely first
- Faulty catalyst temperature sensor 1 or 2 on bank 2Likely
- Sensor drift causing the two readings to disagreeCommon
- Damaged or corroded sensor wiring or connectorCommon
- Open or short between a sensor and the ECMLess often
- Actual exhaust temperature anomaly at one sensor (rare)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and compare the two bank-2 catalyst temperature sensor readings with a scan tool — a warm engine should show both roughly tracking together.
- Inspect both sensor connectors and wiring for corrosion, chafing, or loose pins.
- Replace whichever sensor is reading out of range or lagging the other.
- If both sensors and wiring check out, verify there's no exhaust leak near a sensor, then clear and re-test.
FAQ
Quick answers
Is it safe to drive with P046B?+
Yes — this correlation code doesn't affect drivability. It mainly means the ECM can't trust the catalyst temperature data, so the emissions monitor won't pass until it's fixed.
Can I just clear P046B?+
You can clear it, but if the two sensors still disagree the code returns after the next drive cycle. Diagnose the sensor or wiring first.
Related codes
Read & clear P046B 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