Circuit Description

WARNING: This page is about a different car, the 1997 Pontiac Bonneville, 1997 Oldsmobile Regency, 1997 Oldsmobile LSS, 1997 Oldsmobile Eighty-Eight, and 1997 Buick LeSabre. However, it is still accessible from the selected car via links, so may be relevant.

PCM reads Heated Oxygen Sensor (HO2S) activity for 100 seconds. During this period, PCM counts the number of Lean/Rich (L/R) and Rich/Lean (R/L) switches.

With this information, an average time for all transitions can be determined. PCM then divides R/L average by L/R rich average to obtain a ratio. If HO2S ratio is not within range, DTC P1134 will set.

Conditions required to set DTC are:

No fuel trim, injector or HO2S 1 heater circuit DTCs set.
No ECT, IAT, MAF, MAP, or TP sensor DTCs set.
No EGR or EVAP DTCs set.
Engine operating in closed loop mode.
Listed conditions present during 100 second monitoring period.
TP angle value 10-20 percent.
Ratio of average response times not 3.00-0.75 on VIN 1.
Ratio of average response times not 4.50-0.50 on VIN K.