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 is having trouble with the oxygen sensor on the first side of the engine. It's like the sensor isn't getting enough power to work properly.
The P2238 code indicates a problem with the oxygen sensor's current control circuit on bank 1, sensor 1. The sensor is not receiving the proper amount of current.
The oxygen sensor in question is responsible for measuring the amount of oxygen in the exhaust gases. The ECM (Engine Control Module) controls the current to the sensor to ensure accurate readings. A 'low' circuit condition suggests that the sensor is not receiving enough current, which could be due to wiring issues, a faulty sensor, or problems with the ECM itself.
• Check Engine Light is on
• Poor fuel economy
• Rough idle
• Faulty oxygen sensor
• Wiring issues or poor connections
• Faulty ECM
ECM: Engine Control Module
OBD-II: On-Board Diagnostics, Second Generation
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connections to the oxygen sensor.
• Test the oxygen sensor for proper operation.
• Replace the faulty oxygen sensor.
• Repair or replace damaged wiring or connectors.
• Reprogram or replace the ECM if necessary.
• OBD-II Scanner
• Multimeter
• Wrench set
$150 - $300
Moderate
• Toyota Camry
• Honda Accord
• Ford F-150
• Regularly inspect and maintain vehicle wiring.
• Keep the engine and exhaust system well-maintained.
• Use high-quality fuel to prevent sensor contamination.
Sensor Issue
• Do not ignore the Check Engine Light.
• Have the vehicle inspected by a professional if unsure.
• Regular maintenance can prevent such issues.
Oxygen sensors may be covered under the vehicle's emissions warranty.
This code has been associated with oxygen sensor failures and wiring issues in various models over the years.
Moderate – Should be addressed to prevent further engine performance issues.
Driving with a faulty oxygen sensor can lead to increased emissions and potential engine damage.
• Engine at operating temperature
• Vehicle in closed-loop operation
The sensor is located on the exhaust manifold of bank 1, which is the side of the engine with cylinder 1.
Q: Can I drive with a P2238 code?
A: It's possible to drive, but it's not recommended as it can lead to poor fuel economy and increased emissions.
Q: How do I know if the oxygen sensor is bad?
A: Symptoms include a rough idle, poor fuel economy, and the Check Engine Light being on.
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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 the code or supporting diagnostics point toward upstream or downstream oxygen-sensor faults.
This code family often involves upstream or downstream oxygen-sensor diagnosis.
Verify exact sensor position and vehicle fitment before buying.
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.