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P0133 O2 Sensor Circuit Slow Response (Bank 1 Sensor 1)
What it means
The upstream oxygen sensor on bank 1 is responding too slowly to changes in the air/fuel mixture — typical of an aging sensor.
Severity: Low to Moderate
Can I drive it? Drivable; fuel economy may drop.
Common causes (most likely first)
- Aging/contaminated upstream O2 sensor
- Exhaust leak near the sensor
- Wiring issue
Likely fixes
- Check for exhaust leaks
- Replace upstream O2 sensor
DIY parts cost
$30–$150
Approximate estimate
Shop repair cost
$150–$400
Approximate estimate, parts + labor
DIY difficulty
Easy to Moderate
Varies by vehicle
Cost ranges are rough, approximate U.S. estimates and vary widely by vehicle, region, and parts brand. Always confirm the diagnosis before buying parts.
Parts you may need
- Upstream oxygen sensorCheck price
- O2 sensor socketCheck price
- Anti-seizeCheck price
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