Fast 30400-KIT-EZ-EF Instructions Manual - page 19

19 

NOTE: Installing the threaded oxygen sensor fitting should be the first step in the installation process. 

It should be done before you begin removing your existing fuel/induction system. That way, you can 

still drive to an exhaust shop if needed.     

Wideband Oxygen Sensor Installation Notes: 

 Install the sensor just upstream of the catalytic converter (if present). The sensor can be

installed after the converter, but the readings will register slightly leaner than if measured

before the converter.

 Ideally, the sensor should be mounted at least 10° above horizontal (wire side up, sensor tip

down). This prevents moisture from collecting in the sensor.

 The sensor should not be installed closer than 20 inches from the cylinder head to ensure

excessive heat does not damage the sensor.

 The sensor should be installed in or after the collector. This gives the ECU an average reading

across an entire bank instead of from just one cylinder.

 The sensor should not be mounted near the open end of the exhaust system. At low engine

speeds, free air may reverberate into the exhaust and cause false readings.

 The system will not function properly if there are any exhaust leaks. Any fresh air that gets to

the sensor will cause false lean readings. The ECU will respond by adding fuel that the engine

doesn’t need.

NOTE: The use of leaded fuel will significantly reduce the lifespan of the oxygen sensor. 

Coolant Temperature Sensor Installation