Okay, I wish I had this when I needed it so I am going to make it for anyone who has an explorer and is smart enough to search this forum.
Obviously you have a problem if you have replaced all of your O2 sensors and you are still throwing a code. Chances are that one of your catalytic converters are bad and if you have 3 catalytic converters like I do, that is not a cheap fix. You probably had the guts of one of your cats fall apart and clogging the last one that they both feed into. You probably want to get that fixed eventually, but if you are in a bind and have to get rid of your check engine light due to an emissions code (P04XX Auxiliary Emission Controls) you can try this to fix it.
Pretty much what this mod will do is give the attenuation values that the ECU is looking for(the capacitor is a +/- 20% component, the resistor +/- 5%). The input voltage measurement at 1.0Hz is due to the loading effect of the capacitor as the input frequency approaches the turnover frequency which is what tricks the ECU and gives it the resistance it's looking for.
So, now you want to know how to do it: I don't have a lot of pics, but the ones I do have are very effective and you should have no questions.
1) Go to Radio Shack and buy the following:
Qty 2: P/N 272-1434 (1 Micro Farad capacitor +/- 20%)
1 pack of P/N 271-1134(1 Mega Ohm 1/2W +/- 5%) you can also use the 1/4W if they don't have the 1/2 in stock. They sell these resistors as a pack of 5
If you don't have flux, solder, a soldering Iron, or heat shrink, you might want to buy that at the time too.
2) Get home and disconnect your rearward O2 Sensor's plug from the harness. More than likely you have 2 of them so be sure to look. There are 2 main set-ups with the 3rd gen:
1. 2 cats located on either side of the Ypipe, (an O2 sensor before and after this primary cat) and a resonator shortly after. then the factory muffler. and 2 1/4'' pipe out the back. ( 02-03 )
2. 2 cats located on either side of the Ypipe, (an O2 sensor before and after this primary cat) with no resonator, then the factory muffler then 2 1/4'' pipe out the back. ( 04-05 )
Just follow the O2 sensor up to where it disconnects and disconnect it.
3) Remove your negative battery terminal so you can reset your computer while you are doing this project
4) Remove your O2 sensor(s) from the y-pipe and bring them inside. I used a 7/8" wrench but there are special "O2 Sockets" out there. It is just a socket with a slit in the side so the harness can stick out of it. It just depends on how easily accessible your sensor is.
5) Here comes the fun part!! Leave the 2 white wires alone!! Pull back the insulation sleeving so you can access the wires. I would not cut it off since it is a high temp covering and it will prevent your wires from getting burned if they come in contact with any exhaust components. Cut the Grey and Black wires somewhere in the middle. I understand most people do not have access to the kind of splices I do so you can make it look like the following picture and solder the wires after you are done. Just imagine the top wire is grey and the bottom is black and make sure you put heat shrink over the wires before you solder so you can slide it over and heat it up. You want to make this weather-proof and so that the wires don't touch each other.
Here is the actual diagram of what you are doing:
This is what mine looked like after I was done:
and then after I put the environmental sleeving on:
Once you are done, slide the factory fiber wove wire shielding back over it and you will never be able to tell anything had ever been done.!!
6) Plug your sensor(s) back in and tighten your O2 Sensor back into your y-pipe.
7) Don't forget to reconnect your negative terminal back to your battery
**Note** If you are doing this for inspection purposes make sure you drive your vehicle for 100 miles before you take it to the inspector or they will tell you to go away and come back after those miles have been driven
