P1133 CHEVROLET Possible Causes
What Does This Mean?
- 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 to Fix Code P1133 CHEVROLET?
Start by checking the “Possible Causes” listed above. Visually inspect the corresponding wiring harness and connectors. Look for damaged components and check for broken, bent, pushed out, or corroded connector pins.
When Is the Code Detected?
If the Powertrain Control Module (PCM) determines that the front HO2S has not switched enough times, the PCM will set the P1133 code.
Possible Symptoms
- Check Engine Light On (or Service Engine Soon Warning Light)
P1133 CHEVROLET Meaning
The Powertrain Control Module (PCM) monitors the activity of the Heated Oxygen Sensor (HO2S) for 90 seconds after closed-loop operation begins. The PCM determines if the front HO2S is operating correctly by counting the number of HO2S-1 Lean/Rich (L/R) and Rich/Lean (R/L) switches.