Indicates increasing time for front oxygen sensor (Bank 1, Sensor 1: input of catalytic converter) to get operating condition/temperature after the cold start. Usually means brakes or shortcuts in- or out- sensor wiring. 


  • Check Engine dashboard light is ON
  • Possible increased fuel consumption 


  • O2 sensor heater wiring or connectors issues
  • Faulty O2 sensor heater element

Severity - low

Does not require immediate replacement, but in a log time perspective could lead to spark plugs foul-out. Increasing fuel consumption and pollution. 


  • Check and replace, if required, front oxygen sensor
  • Check and replace, if required, wiring of front oxygen sensor