HO2S Insufficient Switching Sensor 1
Table of contents
P1133 Possible Causes
- Faulty Heated Oxygen Sensor (HO2S) Bank 1 Sensor 1
- Vacuum leak
- Faulty Heated Oxygen Sensor (HO2S) Bank 1 Sensor 1 harness is open or shorted
- Faulty Heated Oxygen Sensor (HO2S) Bank 1 Sensor 1 circuit poor electrical connection
How do I fix code P1133?
Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector’s pins.
Tech Notes
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Cost of diagnosing the P1133 code
The cost of diagnosing the P1133 code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
P1133 Description
The Powertrain Control Module (PCM) monitors the Heated Oxygen Sensor (HO2S) activity for 90 seconds after closed loop operation has begun. The PCM determines if the front HO2S is functioning properly by counting the number of HO2S-1 Lean/Rich (L/R) and Rich/Lean (R/L) switches.