What Does P20E4 Mean?
The PCM has detected an implausible temperature difference between exhaust gas temperature sensors 2 and 3 on Bank 1. These sensors typically monitor pre- and post-DPF temperatures and should correlate based on system operation.
Common Causes
40%
Failed EGT sensor (sensor 2 or 3) reading out of range
25%
Soot or carbon contamination on sensor affecting accuracy
20%
DPF malfunction, cracked substrate, or melted core affecting temperature differential
10%
Exhaust leak at or near DPF affecting sensor readings
5%
Wiring or connector issue causing sensor signal error
Diagnostic Steps
1
Step 1: Compare live data from sensors 2 and 3 during idle, load, and regeneration - note temperature differential patterns
2
Step 2: Verify both sensors read similar ambient temperature when engine is cold
3
Step 3: Check DPF differential pressure sensor readings to assess filter condition
4
Step 4: Inspect DPF housing and connections for exhaust leaks using visual inspection or smoke test
5
Step 5: Remove and inspect sensors for contamination; test sensor resistance at various temperatures if possible
Estimated Repair Cost
$200 - $2,500
Parts + labor, varies by vehicle and location
The PCM has detected an implausible temperature difference between exhaust gas temperature sensors 2 and 3 on Bank 1. These sensors typically monitor pre- and post-DPF temperatures and should correlate based on system operation.
The most common cause of P20E4 (Exhaust Gas Temperature Sensor 2/3 Correlation Bank 1) is: Failed EGT sensor (sensor 2 or 3) reading out of range
Typical repair costs for P20E4 range from $200 to $2,500, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle can be driven but DPF regeneration control is compromised. May lead to DPF failure, reduced power, and potential for thermal damage if regeneration occurs improperly.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P20E4 to identify the root cause.
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Quick Info
Category
Powertrain
System
Exhaust Aftertreatment System
Difficulty
Type
Generic (SAE)
Recommended Tools
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