I recently got a test pipe and as soon as I turned my car on the saw that wonderful check engine light come on. Pissed me off for sure but I spent the last two weeks reading up on the subject (on po.com and other websites) and I came across the concept of hacking into the O2 sensor wires and inserting a resistor to imitate the voltage that the O2 sensor senses when the car correctly makes "clean" exhaust fumes.
I know that there are other ways to trick the ECU but I didn't feel like spending $30 on a stupid O2 sensor imitator or whatever those devices are that trick the ECU. So I took my chances and went to radio shack and bought me the supplies and did the hack. I'm pleased to say that this "myth" actually solved my problem and the check engine light is no more in my car.
So as a tribute to all of you who are scared to do it, heres my super quick mini writeup with diagrams only on how to trick your O2 sensor in believing that your exhaust is nice and clean.
1) wire cutters
2) wire strippers
3) 1 10 Mega Ohm resistor rated at 1/4 watt or more. - Radioshack P/N 271-1365
4) 2 Butt Connectors - Radioshack P/N 64-3108
5) Clear or Gray Heatshrink that is 1/4x6" or larger, but I found this to be the best size. - Radioshack P/N 278-1610
6) A heatgun or lighter or anything that will make the heatshrink actually shrink.
7) electrical or duct tape/zip ties.
1) get under the car and disconnect the REAR O2 sensor from the socket and from the cat. To disconnect it from the cat is a bit tricky and a special tool is needed. You can get it done at a muffler shop for little to nothing. Instead of trying to think up a good excuse simply tell them that your getting a new cat and that you need to take the O2 sensor out to put it in the new one or you can tell them that the sensor went bad and your replacing it. Anyway, if you don't have the tools to get it off the cat then get some place to do it.
2) assuming that the sensor is off the car and out of the cat your next goal is to expose some of the gray wire, i believe that there are either three or four wiress, a black, 2 whites, and a gray, I THINK. Regardless there is still a gray wire.
3) cut the wire and strip about 1/4-1/2 inch on each side of the gray wire. This gap is where your resistor will go.
4) take out 1 10 MegaOhm resistor and simply insert one end into the butt connector. Then take the gray wire that you just cut (Doesn't matter which side) and insert that into the butt connector and crimp both sides. Now give a light tug to ensure that both the resistor and the wire are both secure.
5) Now slide the heat shrink over that piece and expose the other end of the resistor, the one that hasnt been connected.
6) repeat step 4 except do it with the other side of the resistor and the other side of the wire. Now crimp. There is no wrong way to put in a resister so don't stress out about putting it in in reverse, cause it can be connected both ways.
7) slide the heatshrink so that it covers the whole area that has been worked on and so that it overlaps the factory black wire
8) Now take your heating device and slowly heat the heatshrink so that it shrinks over the resistor and the two butt connectors. This makes sure that no metal or connection of any kind will losen or make contact with the frame or any other part of the car.
9) Take the electrical tape or duct tape and wrap it around the whole O2 sensor cable, or atleast the part the has the heatshrink on it. I wrapped electrical tape around the whole O2 sensor cable.
You should now be done and ready to role! Don't forget to plug the O2 sensor back in the car and you have to disconnect the battery from the car for a second from the car so that the computer will reset. Then just zip tie or duct tape the sensor and the wires to the frame and should be good to go!
Below is a diagram of what a butt connector
Catalog #: 64-3108
Below is what the resistors
10M ohm 1/4W 5% Carbon Film Resistor pk/5
$0.99 Brand: RadioShack
Catalog #: 271-1365 Model: 271-1365
Below is a diagram of what the heatshrink
looks like: The one that I used was the largest clear sized one that came in this pack:
Multicolor Heat-Shrink Tubing
$2.49 Brand: RadioShack
Catalog #: 278-1610 Model: 278-1610
This final diagram is a view of what I just explained should look like:
Don't forget to put tape over this whole deal.
Good luck to everyone, I hope that it is as much of a success for you as it was for me. If you have any questions, comments, or problems let me know.
Hack on my lude brothers!