July 1: So it begins. Don't worry, this is not in the correct legal jurisdiction!

O2 Heater

PURPOSE
To heat the O2 sensor.

LOCATION
An integral part of the O2 sensor.

OPERATION
The O2 sensor does not operate until a certain temperature is reached. The heater warms the sensor up faster than if it had to rely simply on exhaust gas heat. The MPFI system then controls the A/F mixture sooner, reducing exhaust emissions.