P0133
Medium SeverityO2 Sensor Circuit Slow Response (Bank 1, Sensor 1)
Emissions System
What Does P0133 Mean?
The upstream O2 sensor on bank 1 is responding too slowly to changes in exhaust oxygen content. Known as a lazy O2 sensor.
Common Fix
Replace O2 sensor
Estimated Cost (DIY)
$30 - $100
Symptoms
- ⚠️Slightly poor fuel economy
- ⚠️Failed emissions test
- ⚠️Occasional hesitation
- ⚠️Check engine light
Related Symptoms
Common Causes
How to Diagnose P0133
- 1Monitor O2 sensor switching rate (should be 1-3 times/second at 2500 RPM)
- 2Check for oil consumption or coolant leak
- 3Inspect for exhaust leaks
- 4Replace if response time exceeds 300ms
OEM Diagnostic Flowchart
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Related Resources
Repair guides, symptom pages, and wiring diagrams related to P0133.
OEM Manual Evidence
Browse →A L L Diagnostic Trouble Codes ( DTC ) — 2013 GMC Truck Yukon XL 4WD V8-6.0L Service Manual | Operation CHARM Operation CHARM : Car repair...
A L L Diagnostic Trouble Codes ( DTC ) — 2013 GMC Truck Yukon XL 2WD V8-6.0L Service Manual | Operation CHARM Operation CHARM : Car repair...
A L L Diagnostic Trouble Codes ( DTC ) — 2013 GMC Truck Terrain AWD V6-3.6L Service Manual | Operation CHARM Operation CHARM : Car repair m...
A L L Diagnostic Trouble Codes ( DTC ) — 2013 GMC Truck Terrain FWD V6-3.6L Service Manual | Operation CHARM Operation CHARM : Car repair m...
Related Symptoms
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Related Codes
General fault with the upstream O2 sensor on bank 1. This sensor monitors exhaust oxygen to control fuel mixture.
The upstream O2 sensor on bank 1 shows no switching activity. The sensor may be dead or disconnected.
The heater in the upstream O2 sensor on bank 1 is not working properly. The heater brings the sensor to operating temperature quickly.
Frequently Asked Questions
- How long do O2 sensors last?
- Most O2 sensors last 60,000-100,000 miles. After that, they get lazy and respond slowly, triggering P0133.
- Is P0133 a big deal?
- Not an emergency, but fuel economy suffers and you will fail emissions. Replace the sensor when convenient.
Related Repair Guides
If your vehicle has triggered P0133, these DIY repair guides may help: