Catalyst Temperature Sensor 1/2 Correlation (Bank 2)
The P046B code indicates that the Engine Control Module (ECM) has detected a correlation issue between the upstream (Sensor 1) and downstream (Sensor 2) catalyst temperature sensors on Bank 2. This typically means the sensors are reporting temperatures that are not within expected parameters relative to each other, often due to a faulty sensor, wiring issue, or an inefficient catalytic converter. Bank 2 refers to the side of the engine opposite cylinder #1.
1. Most Common Causes
- Internal failure of the catalyst temperature sensor (sensor 1 or 2, bank 2)
- Short, open, or high resistance in the electrical wiring
- Corroded, damaged, or poor-contact connections or terminals in the exhaust system harness
- Faulty catalytic converter on bank 2 (internal degradation or substrate meltdown)
- Significant exhaust leak upstream or between the bank 2 sensors
- Electrical or programming fault in the powertrain control module (PCM)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Decreased fuel economy
- Possible failed emissions test
- Engine performance issues (hesitation, rough idle)
3. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for additional codes.
Step 2: Visually inspect the wiring and connectors for Bank 2 catalyst temperature sensors.
Step 3: Compare live data from Sensor 1 and Sensor 2; they should be similar after warm-up.
Step 4: Test sensor resistance and voltage with a multimeter per manufacturer specs.
Step 5: If sensors are okay, inspect the catalytic converter for damage or clogging.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is generally safe for short distances, but prolonged driving may damage the catalytic converter or cause poor performance. It's best to diagnose and repair promptly.
How much does it cost to fix?▼
The cost varies: sensor replacement is $50-$150, while catalytic converter replacement can be $500-$2000 or more.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.