Articles » PLX Devices Wideband O2 Install

10. THIS IS NOT IN THE PLX PROCEDURE FOR NORMAL USE. ONLY FOR INTERGRATION WITH A STANDALONE EMS.
Now you need to make a resistor jumper for the stock Coil wire (+) and (-) wires. I found in the instructions where they mention if hooking up to a Hondata or AEM system that you need to put a 1K-Ohm Resistor in this spot. (1K Ohm, 5% tolerance, 1/4 Watt power capabilities) These can be purchased at your local radio shack. I know how to read resistors and such, so I stole one off a scrap motherboard I had lying around, so I didn't need to make this trip. Good thing, cause it was about 12 midnight when I made this discovery that I needed this.

Take the resistor and solder it to 2 short pieces of wire. Take your old O2 sensor and cut the connector off of it. Remember, leave yourself something to solder to, cause we are using this connector. There should be 4 wires. 1 white, 1 Green, and 2 Black. Cut all the wires the same length. Then fold the white and green ones over in half and tie wrap to themselves. Leaving just the 2 black wires running straight out. Take your resistor that you have and solder it to these 2 black wires. This is your jumper plug. Cover/ wrap this new little harness thing nicely and plug it back into the stock engine harness position that your PRIMARY O2 was previously plugged into. Now you have to jumper the (+) and (-) Coil wires. This will fool the ECU into thinking the circuit is still there and not throw a CODE 41 CEL when you start the car.
Here is what mine looked like.



This is it installed in the Engine.


11. Now double-check all your connections. Make sure grounds are good. Power is good, and that you have connected everything up. It's time for a test.

12. RESET YOUR ECU!!!!!!!

13. Start the car and check for a CEL. If you get nothing, then you did everything correctly. If you are like me, you are very curious and didn't actually solder all your connections on the first go around. This way you can monitor your outputs from the PLX Controller box. Check the White wire, you should have anywhere from 0v - 5V output. Depending on car's condition and what not, it should read anywhere from 2.0 - 4.0 when first starting. Then come down as it warms up.
Also check the Grey wire output Voltage going to your ECU. It should read .1V - .9V or thereabouts. This is your narrowband output voltage that the ECU needs to read to run your fuel maps and what not in a Closed Loop mode.
If either of these is not producing an output, make sure the power to your Controller box is good. If you got the M-300 then you should have a visual display as well. Also check the ground to be sure it is good.

Now check the output from the Autometer Converter device. On the Orange or Violet line (they connect together remember) there should be a low .1V - .9V reading as well going into your A/F gauge, and your gauge should be lit something like this....

I just started the car, so naturally it's rich. After it warms up, it drops down a few LED's to almost perfect Stoich conditions. Now I can properly adjust my Fuel Pressure and get a better Stoich condition. :)

Okay, so now you are done. Re-install all your plastic panels and clean up your mess you dirty little bastard.

Enjoy!!
:)