Exhaust Gas Temperature Sensor 2/3 Correlation Bank 1
The P20E4 code indicates that the Engine Control Module (ECM) has detected a correlation error between the Exhaust Gas Temperature (EGT) Sensor 2 and Sensor 3 on Bank 1. These sensors monitor exhaust temperature for diesel particulate filter (DPF) regeneration and emissions control. The ECM compares readings from both sensors; if they deviate beyond a calibrated threshold, this code sets. Common causes include faulty sensors, wiring issues, or exhaust leaks.
01. Most Common Causes
- Faulty EGT sensor 2 or 3
- Wiring or connector damage
- Exhaust gas leaks near sensors
- ECM software issues
02. Symptoms You Will Notice
- Check Engine Light on
- Reduced fuel economy
- Possible DPF regeneration issues
- Decreased engine performance
03. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect EGT sensors 2 and 3 for damage or loose connections.
Step 3: Compare sensor readings using a scan tool while engine is running.
Step 4: Check for exhaust leaks between sensors.
Step 5: Test sensor resistance and voltage per manufacturer specs.
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 DPF damage or reduced performance. Short trips may be okay, but have it diagnosed soon.
How much does it cost to fix?▼
Diagnosis typically costs $50-$150. Sensor replacement parts range from $50-$200 each, plus labor. Total repair can be $150-$400.