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I recently acquired a bassani O/R X pipe and decided to do some research and learn how to make my own MIL Eliminators. Since the O2 bungs were located pretty far back on the bassani pipe, I would also have needed to buy O2 extension wires. The total cost for the MILs and the Extensions was going to be about $100, but I instead built my custom setup for only $20 in radio shack parts.

The parts/part numbers from radio shack that you will need are:

#2760148 - PC Board - 1 Package will do. You can break the board in half.
#2721434 - Tantalum Capacitor - You need 2 of these
#2711356 - This is a 5 pack of 1 mega ohm resistors. One pack is enough.

You will also need 20 gauge wire(25 ft. or so), electrical tape, solder, and a soldering iron. If you don't have these items they can also be bought at radioshack.

You will need to remove your stock rear O2 sensors for this process.

Start by carefully cutting off the outer sheathing from the O2 sensor wiring. Once it is off you will notice that there are 4 different wires -- A Gray wire, a Black Wire, and two White wires. You will want to mark one of the white wires because they will have to be matched up in their original configuration when everything is soldered back together.

Next cut through all 4 wire mid way between the connector and the O2 sensor. You will now have 2 separate pieces. Strip the end of all of the wires so that you have about a half inch exposed on each wire.

Cut 4 equal strips of 20 gauge wire and strip the ends of these as well( the length you need will depend on how much of an extension you need -- each brand of midpipe mounts the O2 Bungs in different spots). I used about 2 1/2 feet for each wire.

You will now twist/solder these wires to the two halves of the O2 wiring harness so that it seems you have now just extended the wiring harness. Be sure to pay special attention to matching the wires up correctly. You wouldn't want a black wire now connected to a different color.

Tape up each solder point so that the wires don't touch each other. After each section is tapped you can then add another layer of tape around the entire area for extra strength.

The next step will be to cut the black and gray wire in the middle of the harness(the harness should now be about 3 feet long total and you will want to cut in the middle area so that you can tie wrap it up later away from hot exhaust areas).

Go ahead and strip the wires in the same fashion as before and now you are going to follow the wiring diagram. Solder everything to the pc board as shown in the picture. Be sure to solder on the side of the board that has the little copper circles. The solder will hold everything tight to the copper area.

Be sure to pay attention to which end the Sensor is on and which the connector is on -- IT DOES MATTER.

After everything is soldered up wrap the entire wire area of the harness with the electrical tape. Once all of the steps have been completed you should see the two ends(one the connector and the other the O2 sensors) with electrical tapped wire from end to end.

Undo your battery terminals so that the car has now power.

Screw the sensors back into the pipe and plug the connector ends back into the car.

After getting the sensors plugged back up about 5 minutes should have passed. Put the terminals back onto the battery and you are good to go.

I can't absolutely positively promise you that this will work for your car, but it has for mine and was much cheaper than buying MIL's/Extensions. It works exactly like MILs do so if you have followed the instructions and diagram you should be good to go and not have to look at an annoying check engine light.

found @ http://www.bmcforums.com

There are 39 comments
Rob roy
August 24, 2020 - 09:15 PM

Will these mil eliminators work for the 2011 coyote engines as well or is there enough new technology in the ecm to know when something is not exactly the way it was from the factory. Thank you for your response and greatly appreciate your knowledge

Angel – Greeley
October 06, 2018 - 03:27 AM

Need help please

Chris – Tennessee
June 08, 2018 - 04:43 PM
Subject: M i l eliminators

I have a 2011 Mustang GT 5.0 stainless steel headers no catalytic converters my issue is check engine light comes on due to the back to O2 sensors sends a code where can I get and what is the part number the eliminators for this coyote motor

Bob – WA
January 13, 2018 - 03:18 AM
Subject: I made the same thing

I used the same design on a subaru. So far it working great. It stopped the fuel trim from bouncing all over, as the ecu was trying to fine tune it the mixture with a high flow cat it never could figure it out. Soon as I put this mod on the front O2 and fuel time went to rock steady.

Eddie – Ardmore Al
July 06, 2017 - 09:15 PM
Subject: 2006 Ford E250 4.6L

I made these and it did not work on mine. The MIL came back in within a few minutes. I wire the positive side of the cap to the black wire. Any ideas why this did not work?

Reply to Eddie
July 17, 2017 - 09:26 PM
Subject: mils

Didn't work for me either. I gave up after trying several methods. Ended up just pulling the MIL bulb out of the cluster. Car is sold now.

Fernando – Miami, FL
February 17, 2015 - 09:51 PM
Subject: MIL Eliminator

Hello, Just wondering if this worked on the post about the 05+ 4.6L?


Fritz – Tx
January 31, 2014 - 05:02 PM
Subject: Capacitor

Long end of capacitor is + and short end is -.
So long end goes to blk wire and short to grey.
This will hopefully clarify for those still getting error codes.

Hector – Chicago
December 04, 2013 - 05:11 PM

Just made a set of these, already had wire. Cost me about 6$ for the parts. Ill be back and post how they worked.

Reply to Hector
December 06, 2013 - 11:31 AM
Subject: Re:

Good luck. Post up a picture here when you get around to it!

Lance – United States
September 05, 2013 - 06:53 AM
Subject: Ford V8 in Jaguars

I have the Ford V8 Dual Overhead Cam 4.0 Liter. I think its the same engine found in early Lincoln LS Sports Sedans (though they call it a 3.9).
I have No Cats, replaced front mufflers with cylinder performance mufflers, and 18"x3" Resonator tips -- Will this fix work for me, and should I use 1/2 or the 1/4 resistor .. ?
Thanx Guys .. !

August 14, 2013 - 06:13 PM
Subject: Newer Fords

For newer Mustangs ie 2005+ 4.6 Do we have to use 1/2 watt resistors? I'm getting the code "Rear O2 Stuck Lean"

El peluche – florida
July 28, 2013 - 04:50 PM
Subject: Land Rover Discovery 2 with a 4.6 Bosh V8

Hi there Guy's.. Do u think this also can work on my land rover??? I just did the throttle body groove and now the engine is dumping more gas to keep my exhaust temp up. So i'm not getting much of the gains from the up grade. Just like 2% increase on fuel economy

May 24, 2013 - 05:33 PM
Subject: Re: MIL Eliminators

I used this article to make my own MIL's. I did not need to extend the wires so I just cut the Black and Gray wires and soldered in the resister and capacitors.shrink wrapped and taped.

I did not used the pc board either.

I did this on my 1999 SVT Lightning and it worked great. No more codes for catalyst system.

The MIL's you buy for mustangs/ford are pretty much universal. The 02 sensor wires on my Lightning were Identical.

Thanks for sharing! Saved me 32 dollars.

I spent 18 dollars total Including the Solder and Shrink Wrap

Rafael – Mexico
January 28, 2013 - 02:56 AM

I've got a 00' V6 manual transmission, 94-98 headers.
I gutted my Cats and needed these mil eliminators.
But i only got 104 capacitors.
The P0420 code disappeared and hasn't come back since but the P0430 is still lingering.
I'm changing the capacitor and resistor once again, but my doubt is:
Is a 104 (.1uF Capacitor) the problem? Should I get the 105 (1uF capacitor).

Plus, I've got a 4.7uF(50v) Capacitor lingering around, would that do the trick too? Or could I cause more trouble?

Allan03GT Tn – knoxville tn
December 23, 2012 - 06:48 PM
Subject: mil eliminators

I have built 3 sets of these and none have worked
I am building them just like the photo and the lights keeps coming back on. Should I reverse the black and gray wires? This is on a 03 gt convertible

Reply to Allan03GT Tn
Rafael – Mexico
January 28, 2013 - 03:08 AM
Subject: Yes

Yes you should.

Reply to Allan03GT Tn
March 24, 2013 - 01:17 AM

I made 3 sets and it didnt work also i had to use the 1/2 watt resistor the 1/4 didnt work.

June 13, 2012 - 02:12 AM

Will this work on a 98 Ranger with 2.5L 4cyl?

omar – houston
October 29, 2011 - 06:45 PM
Subject: thank you

they worked on my 02 mustang gt, no MIL and all monitors checked in after a long cruise beats spending 80 dollars.

Reply to omar
April 01, 2012 - 01:55 PM

this works however the black wire is the + and the gray wire is the -. wire the capacitor and the resistor on the positive wire not the gray wire

September 21, 2011 - 07:09 PM
Subject: what about?

what if the rear oxygen sensor is missing like the wires were just cut off at the sensor is there a way to make this still work?

dave – Canada
May 12, 2011 - 01:29 PM
Subject: Wiring

Hey just like the first post, the capacitor has short and long wire. Is the long side connected to the resistor side? Please confirm.

Reply to dave
January 04, 2012 - 11:40 AM
Subject: Capacitor

the capacitor does not have polarity no matter wich one filament

May 06, 2011 - 04:06 PM
Subject: Capacitor

There is a long wire and a short wire coming from the capacitor. In the diagram it looks like the long one attaches to the resistor side of things. Is this correct or does it not matter?

March 17, 2011 - 08:13 PM

this worked for my 2001 Mustang GT ...and it only cost about $10...

Logan – Winfield
February 23, 2011 - 03:50 PM

Will this work on my 96 F150 5.8 liter?

October 03, 2010 - 01:33 PM

This worked on my 09 f150. Didn't use the board though. Wanted to keep it small. Thanks for the help.

Reply to bill
Ahmet – Illinois
August 14, 2013 - 06:11 PM
Subject: MIL question

Dude. I have no idea if you still get messages. When you made your MIL eliminator for your 09 F150. Did you use the 1/2watt resistor. Or made it just like mike did it?

September 29, 2010 - 07:00 AM

if i did this could i gut out my cat and not have my check engine light come on

Reply to adam
Mike – New York
September 29, 2010 - 09:24 AM

Yes, these will prevent your check engine or SES light from coming on.

July 04, 2009 - 02:47 AM

Would this work on my 1997 Ford F-150 4.6 V-8?

Reply to Chris
August 18, 2009 - 12:13 AM
Subject: It should

Yes it should, I would imagine at least.

June 30, 2009 - 07:00 PM
Subject: 2?

You need to make 1 for each side correct? By the way nice write up!

Reply to Brian
July 06, 2017 - 09:19 PM
Subject: 2006 Ford E250 4.6L

I tried this for my van and it has not worked. Any idea on what I might try next? I did not use the board. The positive side of the Cap went to the black wire.

May 15, 2009 - 08:41 PM
Subject: 08 mustang

Will these work on my car becuse i cant find any for it?

Reply to Bud
Mike – New York
May 15, 2009 - 09:32 PM

It should.

T. J. – Mo
December 05, 2008 - 10:03 AM

These do work great. A friend and I built a set two years ago exactly like this and they solved me CEL. Cost 5 bucks or so. I didn't use the board though, wanted to keep things nice and small. Anyone can do this with little to no skill and save money.

John – NY
August 08, 2008 - 10:31 AM
Subject: Nice write-up

Thanks for the write-up. I made these MIL Eliminators following this write-up, and they work like a charm. Keep up the good work Mike!

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