Originally Posted by bigdog7373
I can only answer one if your questions. After you remive the cat you use spark plug antifoulers to space the o2 sensor from the exhaust slightly. It tricks it into thinking the cat has slowed the flow of exhaust and cooled it down
You may have to use different combos of different lengths but it will work.
The O2 sensors aren't looking for cooler or slowed down exaughst. What the pcm is basically doing is comparing the waveform of the upsteram sensor to the downstream sensor. It wantrs to see a big difference, sort of like this:
you can do this using a resistor in the sensor signal line, just know
that will take some trial to get the right value, as you are working with a generated voltage of less than 1 volt.