Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the car's computer thinks the sensors that measure the temperature of the exhaust gases are not agreeing with each other. It's like two thermometers telling you different temperatures for the same thing.
The P20E4 code is triggered when the readings from Exhaust Gas Temperature Sensor 2 and Sensor 3 on Bank 1 do not match as expected.
The exhaust gas temperature sensors are used to monitor the temperature of the exhaust gases leaving the engine. This information is used by the engine control module (ECM) to optimize combustion and reduce emissions. If the ECM detects that the readings from two sensors on the same bank are not correlating properly, it will trigger the P20E4 code.
• Check Engine Light illuminated
• Possible decrease in fuel efficiency
• Potential increase in emissions
• Faulty exhaust gas temperature sensor
• Wiring issues or poor connections
• Exhaust leaks affecting sensor readings
ECM: Engine Control Module
OBD-II: On-Board Diagnostics, second generation
• Use an OBD-II scanner to confirm the code
• Visually inspect the wiring and connectors of the sensors
• Test the sensors for proper operation
• Replace faulty exhaust gas temperature sensor
• Repair or replace damaged wiring or connectors
• Fix any exhaust leaks
• OBD-II scanner
• Multimeter
• Basic hand tools
$100 - $300
Moderate
• Ford F-150
• Chevrolet Silverado
• Ram 1500
• Regular maintenance checks
• Ensure proper exhaust system integrity
• Replace sensors as needed
Sensor Issue
• If the check engine light is on, have the vehicle inspected by a professional.
• Avoid prolonged driving with this code active to prevent potential damage.
Sensor-related issues may be covered under vehicle emissions warranty.
This code has been associated with vehicles that have advanced emission control systems.
Moderate – It should be addressed soon to prevent potential damage to the emission control system.
Driving with a malfunctioning emission system may not comply with emissions regulations.
• Engine running
• Vehicle at operating temperature
The exhaust gas temperature sensors are located in the exhaust system, typically before and after the catalytic converter.
Q: Can I drive with a P20E4 code?
A: While the vehicle may still be drivable, it is recommended to address the issue soon to avoid potential damage to the emission system.
Q: How do I know if an exhaust gas temperature sensor is bad?
A: Symptoms may include a check engine light, poor fuel economy, and increased emissions. A diagnostic scan and sensor testing can confirm the issue.
High-End · Full-system diagnostics
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Network faults often require full-system access instead of a generic code reader alone.
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Universal · Digital multimeter
A solid entry-level multimeter for voltage, continuity, resistance, and basic electrical troubleshooting.
Helpful for checking voltage drops, grounds, and basic circuit health when modules are not communicating.
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Universal · Wire connectors and repair kit
Useful when diagnosis points toward damaged wiring, corroded terminals, or connector repairs.
Useful if diagnosis points toward damaged connectors, wiring, or terminal repairs.
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Fitment Required · Vehicle-fitment part
Relevant when catalyst-efficiency or emissions faults persist after proper diagnosis.
Catalyst-efficiency faults sometimes point toward converter problems after proper testing.
Catalytic converters are highly vehicle-specific and should not be purchased by code alone.
View options on AmazonThese parts may be related to this fault category, but a code by itself does not confirm exact fitment or guarantee that replacing a part will solve the problem.