Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
The car's computer is saying that an oxygen sensor in the engine isn't working right. It's like a nose that can't smell properly, so it can't tell if the engine is running well.
The code P1133 indicates that the Heated Oxygen Sensor (HO2S) for Bank 1 Sensor 1 is not switching between rich and lean conditions as expected.
The P1133 code is triggered when the Powertrain Control Module (PCM) detects that the oxygen sensor in front of the catalytic converter is not switching between rich and lean conditions as it should. This sensor is crucial for monitoring the air-fuel ratio and ensuring optimal engine performance and emissions.
• Check Engine Light is on
• Poor fuel economy
• Rough engine idle
• Increased emissions
• Faulty oxygen sensor
• Wiring issues to the oxygen sensor
• Exhaust leaks
• Fuel pressure problems
• PCM issues
PCM: Powertrain Control Module
HO2S: Heated Oxygen Sensor
• Use an OBD-II scanner to confirm the code.
• Inspect the oxygen sensor and its wiring for damage.
• Check for exhaust leaks near the sensor.
• Test the sensor's voltage and resistance.
• Replace the faulty oxygen sensor.
• Repair or replace damaged wiring.
• Fix any exhaust leaks.
• Ensure proper fuel pressure.
• OBD-II scanner
• Multimeter
• Wrench set
$150 - $400
Moderate
• Toyota Camry
• Honda Accord
• Ford F-150
• Regular maintenance checks
• Timely replacement of sensors
• Ensure proper fuel quality
Sensor Issue
• Get the car inspected by a professional.
• Do not ignore the Check Engine Light.
• Maintain regular vehicle service schedules.
Oxygen sensors may be covered under emissions warranty; check with your manufacturer.
This code has been common in vehicles with aging oxygen sensors, particularly in models over 100,000 miles.
Moderate – Should be addressed soon to prevent potential engine damage and increased emissions.
Driving with a faulty oxygen sensor can lead to increased emissions, which may not comply with legal standards.
• Engine at operating temperature
• Vehicle in closed-loop mode
The oxygen sensor is located in the exhaust manifold before the catalytic converter on the engine's Bank 1 side.
Q: Can I drive with a P1133 code?
A: It's possible to drive, but it's not recommended as it can lead to poor fuel economy and potential engine damage.
Q: How long does it take to fix a P1133 code?
A: The repair can take 1-2 hours depending on the specific issue and vehicle model.
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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.
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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.