Faulty EGT sensor 1 or sensor 3 (most common); Damaged or corroded wiring or connector at either EGT sensor; Exhaust leaks upstream of the sensors causing temperature discrepancies; Restricted exhaust flow or a failing diesel particulate filter (DPF) affecting sensor readings; PCM software calibration issue or internal fault; Sensor installed with incorrect torque or heat transfer paste missing

DTC codes / P20xx · Fuel and air metering and auxiliary emission controls / P20E3

P20E3Exhaust Gas Temperature Sensor 1/3 Correlation (Bank 1)

Q: What does code P20E3 mean?

Exhaust Gas Temperature Sensor 1/3 Correlation (Bank 1). P20E3 indicates that the powertrain control module (PCM) has detected an implausible correlation between the exhaust gas temperature (EGT) sensor 1 and EGT sensor 3 on bank 1, meaning the two sensors are not reporting temperatures that agree within the expected range. The PCM compares their readings under specific operating conditions and sets this code when the difference exceeds a calibrated threshold for a set time.

P20E3 indicates that the powertrain control module (PCM) has detected an implausible correlation between the exhaust gas temperature (EGT) sensor 1 and EGT sensor 3 on bank 1, meaning the two sensors are not reporting temperatures that agree within the expected range. The PCM compares their readings under specific operating conditions and sets this code when the difference exceeds a calibrated threshold for a set time.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering and auxiliary emission controls

Symptoms you may notice

Malfunction indicator lamp (MIL) illuminated, often with no other symptoms
Reduced engine power or limp mode in some vehicles
Poor fuel economy or sluggish acceleration
Black smoke or excessive exhaust odor from incomplete combustion
In rare cases, engine overheating or turbocharger damage if temperatures are misreported

Common causes, most likely first

Faulty EGT sensor 1 or sensor 3 (most common)
Damaged or corroded wiring or connector at either EGT sensor
Exhaust leaks upstream of the sensors causing temperature discrepancies
Restricted exhaust flow or a failing diesel particulate filter (DPF) affecting sensor readings
PCM software calibration issue or internal fault
Sensor installed with incorrect torque or heat transfer paste missing

How to diagnose and fix it

Use a scan tool to record live EGT sensor 1 and 3 readings during a test drive and compare them to each other and to expected values.
Visually inspect the sensors, connectors, and wiring for damage, corrosion, or loose connections; repair as needed.
Check for exhaust leaks before the sensors using a smoke test or visual inspection of gaskets and pipes.
Swap the two sensors (if accessible and identical) to see if the fault follows the sensor, confirming a sensor failure.
Test sensor resistance and voltage output according to the manufacturer's specifications; replace faulty sensors.
Verify exhaust system backpressure and DPF condition; repair restrictions if found.
Clear the code and perform a relearn or adaptation drive cycle; if the code returns, check for PCM software updates.

Correlation Codes Often Mislead

A correlation code does not tell you which sensor is wrong; both sensors may be reading incorrectly, so always compare live data rather than replacing parts blindly.
Exhaust leaks upstream of the sensors are a frequently overlooked cause because they can cool one sensor more than the other, creating a false correlation fault.
On some vehicles, a weak battery or charging system issue can cause erratic sensor readings and set this code without any sensor being defective.
After replacing an EGT sensor, the PCM may require a adaptation or relearn procedure; skipping it can cause the code to return immediately.
This code is often stored alongside other EGT or DPF codes, so diagnosing the root cause may require addressing multiple faults together.

Can I keep driving with P20E3?

You can usually drive the vehicle with this code, but avoid heavy loads or sustained high-speed driving until it is diagnosed, as incorrect EGT readings can lead to poor performance or, in severe cases, engine damage. If the vehicle enters limp mode or you notice overheating, stop driving and seek professional diagnosis.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.