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Mil eliminators

Discussion in 'New Edge Cobras' started by Fordman1994, Jun 21, 2019.

  1. Fordman1994

    Fordman1994 New Member Established Member

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    What are Mil eliminators? Are they like an o2 sensor that go into the exhaust? I've never messed with them. Have an 01 cobra. Started getting a p0171 every two tanks or so. Tried cleaning maf. Made it worse. Now it throws both p0171 and p0174. Replaced maf. Now it throws p0171 and p0174 and more frequently. I checked for exhaust leaks/vacuum leaks. Replaced o2s. Took it to Ford all they found was the egr was leaking. One of the bolts was broke. Only had one holding it. I fixed that. Still no change. Anyway It has a catless x pipe. I've never had a code for the rear o2s. It looks like a regular o2 to me. There isnt anything in between it and the harness either. Shouldn't it be throwing a code? I'm thinking maybe it was tuned. Then I messed with the maf now its reading the airflow different and messed with the tune. Short terms is at .8-.9 the long terms are at 1.24. My wideband is reading 13. Isnt that rich?Any help would be appreciated. This is driving me nuts. Oh and It also has a large evap leak. Ford smoke tested and pressure tested it. They told me the gas cap was probably loose. That's not what it is though. Its had that since I bought it and always throws the p0455. Not sure if that would make it lean.
     
    Last edited: Jun 22, 2019
  2. Revvv

    Revvv Infinity Poster Established Member

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    A MIL eliminator is nothing more than an inline, plug in, resistor that tricks the computer. The computer is looking for a number from the rear O2 sensors, and MIL eliminators simulate the number needed.

    Sent from my [mind] using the svtperformance.com mobile app
     
  3. slo984now

    slo984now AKA 01yellerCobra Established Member

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    Those codes are for the upstream O2 sensors. They have nothing to do with the rear O2's. 13 is rich under part throttle, but it's fine under WOT. Usually if it's both codes there's a leak somewhere. It could even be the rubber intake itself.

    As mentioned the MIL's are there to trick the ECU. They're only for the rear O2's though.
     
  4. decipha

    decipha Active Member Established Member

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    sounds like you have a few different issues.

    Definitely need to diagnose it.
     
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  5. 52merc

    52merc Active Member Established Member

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    MIL Eliminators are more than just a resistor. They utilize a transistor as well and some other simple circuitry which actually makes a varying voltage signal which simulates a good signal coming from an O2 sensor. The ECU needs to see the signal vary within an acceptable range or it will throw a code (factory tune). When you use MIL Eliminators you connect them to the downstream O2 sensor harness instead of the actual sensors. They originally were used when long tubes were installed without a tune. During the early years of electronic engine controls, it was difficult to find anybody that understood tuning and reprogramming. These days there is just so much information and many good tuners, that most people get the requirement of the downstream O2 sensor signals turned off in a tune rather than using MIL Eliminators.
     
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  6. shurur

    shurur Well-Known Member Established Member

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    The DIYs that I looked at the mil eliminators were just a cap and a resistor...they just need to be soldered with high temp solder..i.e. plumbing solder.

    Also..depending on what state you are in, tuners are reluctant to turn them off these days, as the govmnt is cracking down on it.

    Any..as said..problem is for s1 o2s
    DIY "MIL" elimiators?..Anyone know how?
     
    Last edited: Jun 21, 2019
  7. Fordman1994

    Fordman1994 New Member Established Member

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    Okay. It definitely doesn't have any mil eliminators. I know the codes are for the upstream. I dont have cats though and I dont get any codes for the downstream. Which makes me think it has a tune. I'm going to take it to Ford and have them see if it has the stock tune.
     
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  8. Revvv

    Revvv Infinity Poster Established Member

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    I just gave a simplified description.

    Sent from my [mind] using the svtperformance.com mobile app
     
  9. Fordman1994

    Fordman1994 New Member Established Member

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    The wideband shows 13 at idle. It's like 13.8 crusing down the highway.

    Just two problems. Couldnt care less about the emissions crap right now unless its causing the lean issue. I doubt it though.
     
  10. slo984now

    slo984now AKA 01yellerCobra Established Member

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    Were you not given a tuning device when you bought the car? Either the wideband needs to be calibrated or the tune is waaayyyy off.
     
  11. Fordman1994

    Fordman1994 New Member Established Member

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    Nope. I bought it from a guy who bought it off the guy who did the exhaust, t56 swap etc. Is that really rich?
     
  12. Fordman1994

    Fordman1994 New Member Established Member

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    Anybody know what gear I would have if I'm at 2400 rpms doing 70mph? It has a t56. I dont think the gears are stock.

    Tried going to Ford nobody there to test my car for the stock tune. Going to try and go monday.
     
  13. decipha

    decipha Active Member Established Member

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    The dealer has no way of knowing if its a stock tune they can only wrote a stock tune to it and if they do the car may not be driveable. Thats the absolute worse thing you could do to try to diagnose the car.

    The ONLY way to properly diagnose the car is to be able to see and manipulate what the ecu is doing.

    Save yourself the frustration. Order a moates quarterhorse from moates.net

    Read over this getting started write up to get the free software setup. Read your current tune out and post it on efidynotuning. Someone there if not myself will tell u if its a stock tune and even give you pointers or even fix the tune if its something simple.

    Getting Started / EFIDynoTuning
     
  14. Fordman1994

    Fordman1994 New Member Established Member

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    What all can you do with that? Can you shut the egr off, rear o2s and change the speedo calibrations for different rear gears? Do I need that quarter horse, jaybird and the chip?
     
  15. decipha

    decipha Active Member Established Member

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    yep and no
     
  16. MrMax

    MrMax New Member

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    depending upon your actual tire size...My guess is 4.10
     
  17. shurur

    shurur Well-Known Member Established Member

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    As MrMax said..4.10
    Mustang Rear Gear Ratio to RPM Chart
     
  18. Fordman1994

    Fordman1994 New Member Established Member

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    I ordered a sct x4. If the car had a custom tune could I still use the canned tunes from my sct? I was able to change the gear ratio, tire size etc..
     
  19. decipha

    decipha Active Member Established Member

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    no sct isnt capable of modifying the tune on it already

    you need a moates quarterhorse to do that
     
  20. Fordman1994

    Fordman1994 New Member Established Member

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    I was going to get a tune from vmp. Then have Ford reflash the ECU to stock and install my email tune after. I thought about the quarter horse but I dont know how to tune or what to look for.
     

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