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you can make them cheap from radio shack, i think i spent 5 dollars total on mine

list of part numbers and names from radio shack

RS p/n 272-1434 -- 1.0uF 20% dipped tantalum capacitor ($1.59 each as of this writing)

RS p/n 271-1356 -- 1.0 M Ohm 1/4 Watt 5% carbon film resistor ($0.99 for 5 as of this writing)
-or-
RS p/n 271-1134 -- 1.0 M Ohm 1/2 Watt 5% carbon film resistor ($0.99 for 5 as of this writing)



 

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Stal- did you hard wire them to the harness or O2 sensor?

It would be even better if you could fashion it as a seperate piece with connectors on either end, but I find the connectors are difficult to find.
Here's the link to my site, with the complete description and a Mustang specific wiring diagram.

In answer to your question, the best method is to connect them into the sensor wires. That way you have not bitched up the harness.

Go to Harbor Freight and buy a full compression crimping tool, then use butt connectors¹ filled with dielectric grease. Slip heat shrink tubing onto the wire before crimping, or use electrical tape to tape things up.

The OEM connectors cost $3 to $5 each in quantity, much more than that if you can find them singly, so they are not a viable option--that's why the commercial plug-n-play units cost so much...

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¹ - Some will freak-out over the use of crimped connectors, however truth is that with full compression crimping, and potted with dielectric grease, the connection will be at least as good, and arguably better, than a soldered connection.

There are no soldered connections in the OEM wiring harness--they are all crimped, again using the proper tool for the terminal in question...
 

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Stal- did you hard wire them to the harness or O2 sensor?

It would be even better if you could fashion it as a seperate piece with connectors on either end, but I find the connectors are difficult to find.
i hard wired mine in the o2 senser wires them self. it is a lot easier to do that way cause you can pull your o2 sensers out and work on a table. only thing that stinks is if your o2 goes out you have to make another set of mil's.
 

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i used spark plug non-foulers and haven't had any trouble yet. only cost about $5 or $6 on them at autozone.
They will work on many vehicles, all that needs to be done is slow down the switching frequency and signal amplitude at the rear sensors--the extended "sample chamber" introduced by the non-foulers creates a somewhat stagnant sample environment for the sensor that will often fool the PCM.

Did you have to drill them out for the O2 sensor to fit?
 

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non foulers are hit or miss. they often work for a period of time then you will get a cel for it. not a big deal though just reset the computer. you can get a single non fouler to fit if you cut the sheild off the o2 senser, other wise you may have to drill one and stack the second one.
 

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I keep forgetting to post this--it's an alternative way of making a MIL eliminator that sometimes works when others fail:

Here's the schematic for splicing it in to a New-Edge Mustang:


The diode rectifies the signal from the rear sensor, and because of it's inherent voltage drop also reduces it amplitude.

And here's a 'scope trace of a 5.0Hz 0.45V square wave (top) being passed through a 1N4001 silicon diode:


Note that the amplitude has been reduced from 493mV to 150mV...
 

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i drilled out the center of the non fouler to a certain depth. i found that if i drilled it completely through the car would throw a cel, but if i left the smaller diameter hole at the bottom, it has done just fine. i've had it on there for about 9 months and haven't had any problems out of it.
 

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i drilled out the center of the non fouler to a certain depth. i found that if i drilled it completely through the car would throw a cel, but if i left the smaller diameter hole at the bottom, it has done just fine. i've had it on there for about 9 months and haven't had any problems out of it.
That makes sense, you need to create that stagnant pool of exhaust gas to make the rear sensor trick the PCM...
 

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Discussion Starter #13
Will the cel from a o/r midpipe cause the car to run bad? Because im wanting to order a tuner in a couple weeks so I dont see the point in paying money for mils right now when I wont be using them very long anyway.
 

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Will the cel from a o/r midpipe cause the car to run bad? Because im wanting to order a tuner in a couple weeks so I dont see the point in paying money for mils right now when I wont be using them very long anyway.
No, all the rear sensors do is monitor the catalytic converter efficiency--they have no role in engine control.

One thing to be aware of is that disabling the rear sensors in the tune will also make the PCM report that the catalytic converter monitoring system is inactive when a scan tool requests the I/M (Inspection/Maintenance) Readiness status.

In some states this will be an automatic fail for the emissions test; in such places MIL eliminators are a better solution as they trick the PCM into believing that the catalytic converters are present and working.
 

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Discussion Starter #15
No, all the rear sensors do is monitor the catalytic converter efficiency--they have no role in engine control.

One thing to be aware of is that disabling the rear sensors in the tune will also make the PCM report that the catalytic converter monitoring system is inactive when a scan tool requests the I/M (Inspection/Maintenance) Readiness status.

In some states this will be an automatic fail for the emissions test; in such places MIL eliminators are a better solution as they trick the PCM into believing that the catalytic converters are present and working.
I dont have emissions testing where I live.
 

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Cool, we don not have any inspections at all here in Florida...
 
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