P1127 FORD – Exhaust Not Warm Enough Downstream O2 Sensor Not Tested

P1127 FORD Possible Symptoms

Engine Light ON (or Service Engine Soon Warning Light)

P1127 FORD Possible Causes

Faulty O2 Sensor Heaters,O2 Sensor Heaters harness is open or shorted,O2 Sensor Heaters circuit poor electrical connection

P1127 FORD Description

The heated oxygen sensor (HO2S) monitor uses an exhaust temperature model to determine when the HO2S heaters are cycled ON. The test fails when the inferred exhaust temperature is below a minimum calibrated value.