P046A
Catalyst Temperature Sensor 1/2 Correlation Bank 1
Emissions / catalyst
Generic OBD-II
Medium
What it means
P046A means the two catalyst temperature sensors on bank 1 are reporting readings that don't agree with each other. The ECM cross-checks these sensors to monitor converter temperature; when they disagree it flags a correlation fault. It's usually a bad sensor, wiring, or an exhaust leak — but it can also point to a genuinely overheating catalyst, so it's worth diagnosing.
Medium
Can I keep driving? Yes — the car starts and drives normally. It's an emissions monitoring fault, but a real catalyst overheating issue behind it could damage the converter, so don't ignore it.
Common symptoms
What you'll notice
- Check-engine light on
- Often no noticeable driving symptoms
- Possible slight loss of power if the catalyst is actually overheating
- Failed emissions test
Common causes
Most likely first
- Faulty catalyst temperature sensor 1 or 2 (giving mismatched readings)Likely
- Damaged wiring, corroded connectors, or poor connections at either sensorCommon
- Exhaust leak between the two sensors skewing the readingsCommon
- Genuine temperature difference from an overheating or degraded catalytic converterLess often
- ECM fault (rare)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and compare the two catalyst temperature sensor readings with a scan tool.
- Inspect both sensors' wiring and connectors for damage, corrosion, or loose pins.
- Check for exhaust leaks between the sensor locations.
- Test each sensor against spec and replace the one reading incorrectly.
- If both sensors check out, investigate the catalytic converter and upstream causes (misfire, rich/lean running). Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P046A?+
Usually yes in the short term — the car runs normally. But if the codes points to a genuinely overheating catalyst, sustained driving could damage the converter, so have it checked.
Can I just clear P046A?+
It will return until the sensor, wiring, or exhaust cause is fixed. This is a correlation code, so the two sensors must agree before it clears for good.
Related codes
Often seen with P046A
Read & clear P046A 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