Code 61 - Degraded O2 Sensor

If a Code 61 is stored in memory, the ECM has determined the Oxygen (O2) sensor is contaminated or degraded because the voltage change time (cross counts) is slow or sluggish.

The ECM performs the O2 sensor response time test when the coolant temperature is more then 185°F (85°C), MAT temperature is greater than 50°F (10°C), system is in "closed-loop" or in a "decel" fuel cut-off mode. If Code 61 is stored, replace the O2 sensor.