Severity High
P043B

Catalyst Temperature Sensor Circuit Range/Performance Bank 2 Sensor 2

📅 Last reviewed: July 2026
What does the P043B code mean?

The P043B code indicates that the Engine Control Module (ECM) has detected a malfunction in the catalyst temperature sensor circuit for Bank 2, Sensor 2. This sensor monitors the temperature of the catalytic converter to ensure efficient operation and protect against overheating. The code is set when the sensor signal is out of the expected range or the sensor response is slower than expected, often due to a faulty sensor, wiring issues, or exhaust leaks.

High
Severity
$50-$150
Typical Cost
High
Frequency

1. Most Common Causes

2. Symptoms You Will Notice

3. Step-by-Step Diagnosis

1

Step 1: Use an OBD2 scanner to confirm the code and check for other related codes.

2

Step 2: Visually inspect the sensor and wiring for damage, corrosion, or loose connections.

3

Step 3: Test the sensor's resistance and voltage output with a multimeter and compare to manufacturer specs.

4

Step 4: Check for exhaust leaks upstream of the sensor that could affect readings.

4. Frequently Asked Questions

Is it safe to drive with this code?

It is not recommended to drive long distances as the catalytic converter may overheat, leading to expensive damage. Short trips to a repair shop are acceptable.

How much does it cost to fix?

The cost typically ranges from $50 to $150 for a new sensor, plus labor if you have it installed professionally.

5. Commonly Affected Makes

This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.

6. Related Codes

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