This will be a continuing thread documenting the test procedure and results of WOODY'S (02 Simulator) fondly referred to as WOODY'S GIZMO.



The GIZMO was built to test the possibility of manipulating the fuel trim and timing advance / retard via the voltage output of the primary and secondary 02 sensors. Being the genius that our fellow member is, Woody whipped this thing up in his top secret laboratory in England and decided that I was the only person stupid enough to test it out on my engine and risk blowing it up Actually because I have removed all my CATS, my engine is the perfect test bed for this process.

That being said, I finally have a few days off work to install the thing and do some extensive testing and document the outcome... For those of you who are not familiar with how the 02 sensors operate, I have copied this section from the service manual.

UPSTREAM OXYGEN SENSOR
The input from the upstream heated O2 Sensor tells the PCM the oxygen content of the exhaust gas. Based on this
input, the PCM fine tunes the air-fuel ratio by adjusting injector pulse width.

The sensor output varies from 0 to 1 volt, depending upon the oxygen content of the exhaust gas in the exhaust
manifold. When a large amount of oxygen is present (caused by a lean air-fuel mixture), the sensor produces volt-
age as low as 0.1 volt. When there is a lesser amount of oxygen present (rich air-fuel mixture) the sensor produces
a voltage as high as 1.0 volt. By monitoring the oxygen content in the exhaust gases and comparing that to the
oxygen content in ambient air and converting it to electrical voltage, the sensor acts as a rich-lean switch.
The heating element in the sensor provides heat to the sensor ceramic element. Heating the sensor allows the
system to enter into closed loop operation sooner. Also, it allows the system to remain in closed loop operation
during periods of extended idle.

In Closed Loop, the PCM adjusts injector pulse width based on the upstream heated oxygen sensor input along with
other signals. In Open Loop, the PCM adjusts injector pulse width based on preprogrammed (fixed) values and
inputs from other sensors.

DOWNSTREAM OXYGEN SENSOR
The downstream heated O2 Sensor signal is used to detect catalytic converter deterioration. As the converter dete-
riorates, the signal from the downstream sensor begins to match the upstream sensor signal except for a slight time
delay. By comparing the downstream heated oxygen sensor signal to the signal from the upstream sensor, the PCM
calculates catalytic converter efficiency. This calculation is also used to establish the upstream O2 goal voltage
(switching point).

I'm off to the electronics store to buy some 20 gauge wire and snap connectors, to start the process... Stay Tuned...