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Old 05-29-2012, 01:03 PM
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sbchevfreak sbchevfreak is offline
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Here is how it works, without getting into too much detail:

The 02 sensor is just that, it senses how much residual oxygen in in the exhaust stream. There is a material in the sensor tip, that generates a voltage between 0v and 1v, roughly, when exposed to oxygen. The sensor has to be at or above 660* F to work, which is why the old 1 wire sensors were mounted in the manifold, so that the exhaust would heat them quickly. At .450-.500 volts, this is the "ideal" mix. Above and below, rich/lean. This cycles in the milisecond range. A fixed voltage will not work, and you cannot manually switch it fast enough.

fbird's idea with the 4 wire sensor mounted furthur down the pipe is a good one. The sensor will be every bit as accurate, likely even more so, as the original. The heated sensors were brought into use because the 1 wires had a tendancy to cool off below threshold, and drop the fuel system into open loop, increasing emissions. The solution was to add a heater circut that was ECM controlled to maintain sensor themp above threshold. In reality, all the early ECM did was turn on the 12v feed to the heater when the car was stared, and turn it off when the car was shut off, so a switched power realay feeding 12v to the heater circut does exactly the same thing.

Your methods will not work. It is time to be rational, and realize that by the time you "engineer" a complicated jimmy fix to fool the ECM, you will have spent more time and money than the car is worth. If you do not want to put in a heated sensor down stream of the original one, you need to remove the original sensor, and replace it. There is no in between.
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