P242A: Exhaust Gas Temperature Sensor Circuit Bank 1 Sensor 3
The P242A code indicates a problem with the exhaust gas temperature (EGT) sensor circuit for Bank 1, Sensor 3. This sensor monitors exhaust temperature to protect the catalytic converter and DPF from overheating. The PCM detects an open, short, or out-of-range signal from the sensor, often due to wiring issues, sensor failure, or exhaust leaks.
01. Most Common Causes
- Faulty exhaust gas temperature sensor
- Open or shorted wiring in sensor circuit
- Corroded or damaged connector
- Exhaust leak near sensor
- PCM software or hardware issue
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine performance or limp mode
- Increased exhaust emissions
- Possible regeneration issues in diesel engines
03. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect EGT sensor wiring and connector for damage or corrosion.
Step 3: Test sensor resistance and voltage with a multimeter per manufacturer specs.
Step 4: Check for exhaust leaks near the sensor location.
Step 5: Replace sensor if tests indicate failure, then clear codes and test drive.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as it can lead to catalytic converter or DPF damage. Short trips to a repair shop are okay.
How much does it cost to fix?▼
Typically $150-$400 including parts and labor, depending on vehicle and sensor location.