DTC P1133 - HO2S INSUFFICIENT SWITCHING SENSOR 1 Oldsmobile Cutlass VI

Note. For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

PCM monitors Heated Oxygen Sensor (HO2S) activity for 100 seconds. PCM determines if HO2S 1 is functioning properly by counting number of HO2S 1 Lean/Rich (L/R) and Rich/Lean (R/L) switches. If PCM determines that HO2S 1 did not switch enough times, DTC 1133 is set.

Conditions required to set DTC are

1. No CKP, ECT, EGR pintle position, IAT, MAF, MAP, or TP sensor DTCs set.
2. No fuel trim, injector or HO2S 1 heater circuit DTCs set.
3. No EVAP system DTCs set.
4. Engine operating in closed loop mode.
5. Conditions present during 100 second monitoring period.
6. HO2S 1 L/R and R/L switches less than 45.