Catalyst Temperature Sensor 1/2 Correlation (Bank 2)
The P046B code indicates that the Engine Control Module (ECM) has detected a correlation error between the two catalyst temperature sensors on Bank 2. Bank 2 refers to the side of the engine opposite cylinder #1. Sensor 1 is typically located before the catalytic converter (upstream) and Sensor 2 after it (downstream). The ECM compares the temperature readings from both sensors to monitor catalytic converter efficiency. When the readings are out of expected range or not correlating, this code is set. This can be caused by faulty sensors, wiring issues, exhaust leaks, or a failing catalytic converter.
01. Most Common Causes
- Faulty catalyst temperature sensor 1 or 2 on Bank 2
- Wiring or connector issues in the sensor circuit
- Exhaust leaks near the sensors
- Failed or clogged catalytic converter
- ECM software or hardware problem
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced fuel efficiency
- Possible failed emissions test
- Engine running rough or misfiring
03. 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 for damage or corrosion.
Step 3: Compare live data from both sensors using a scan tool; temperatures should be similar under steady driving conditions.
Step 4: Check for exhaust leaks near the sensors using a smoke machine or listening for hissing sounds.
Step 5: If sensors and wiring are okay, test the catalytic converter efficiency with a backpressure test or temperature rise test.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is generally safe to drive short distances, but prolonged driving may cause further damage to the catalytic converter or other components. It's best to diagnose and repair promptly.
How much does it cost to fix?▼
The cost varies depending on the cause. Replacing a sensor typically costs $50-$150 including parts and labor. If the catalytic converter needs replacement, costs can range from $500-$2,000 or more.