P1157 Lack Of HO2S22 Switch Sensor Indicates Lean

Possible causes
  • Pinched, shorted, and corroded wiring and pins.
  • Crossed sensor wires.
  • Exhaust leaks.
  • Contaminated or damaged sensor.
    • Symptoms
    – Engine Light ON (or Service Engine Soon Warning Light)
    P1157 Description
    The downstream HO2Ss are forced rich and lean and monitored by the PCM. The test fails if the PCM does not detect the output of the HO2S in a calibrated amount of time.
    P1157 Information for specific makes
    P1157 BUICK
    P1157 CADILLAC
    P1157 CHEVROLET
    P1157 FORD
    P1157 GMC
    P1157 HONDA
    P1157 ACURA