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Discussion Starter · #1 ·
I purchased a 05 st a little over a year ago. A couple weeks after i had it, i was doing some spirited driving through some canyon roads and the check engine light started blinking, then stayed constant. I took it back to the dealer and they said it was a "random misfire" and reset it.

The light has never come back on, except wen u first turn it on (like it should). So lately ive been trying to resolve some hesitation issues and became curious as to why the check engine light has never come back on. I thought unplugging some things would cause it to come on. so i unplugged the MAF sensor. It started and ran kinda rough but no light. ...unplugged a coilpack. no light.

So now im wondering what does it take to cause the light to come on and is it possible for a dealer to disable it jus so i dont bother them anymore???
 

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FOCUS REVOLUTION
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No its not possible to disable it. You have to drive a few miles before a cell will come on for most problems. The fault has to occur three times before a cel is triggered
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Jetsetter
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yes a dealer can disable your check engine light, they do it by fixing the problem!
 

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Meh.
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You really wouldn't want them to disable it even if they could because it can save you a lot of pain later if something really starts going wrong in your engine. The Check Engine light is not there to annoy you, it is there to protect you from costly repairs and engine failure.
 

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You really wouldn't want them to disable it even if they could because it can save you a lot of pain later if something really starts going wrong in your engine. The Check Engine light is not there to annoy you, it is there to protect you from costly repairs and engine failure.
I think he is asking because he thinks maybe the dealership disabled it on purpose so the light wouldnt come back on so they wouldnt need to deal with it anymore..not bc he wanted it disabled.
 

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Hatch Nation #136
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A check engine light can be turned off by unplugging the negative battery cable. If it is still broken, the light will come back. It can be disabled by a tune. That one isn't turning back on until whatever wasn't fixed breaks something else that throws another code.

A sufficiently shady dealership could do this without your knowledge. It is just unlikely.
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FF Affiliate
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I can 100% turn off the CEL and it will never come back on till I turn it back on , If I have that ability I am sure Ford does as well

Just because the "Light" is turned off does not mean you cannot still read any codes that may be set by sensors its just the light thats off

Tom
 

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Ford will not do it. Its how they make money, not to mention its illegal as its a central part of the cars emissions equipment.
 

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I can 100% turn off the CEL and it will never come back on till I turn it back on , If I have that ability I am sure Ford does as well

Just because the "Light" is turned off does not mean you cannot still read any codes that may be set by sensors its just the light thats off

Tom
Does this mean that if you have a tune the check enine light will never come back on? Or will it just not turn on for the reason in which you got the tune for (rear o2 sensor from a header for example)
 

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w/ my magic bag
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Your the least of their problem's= don't worry 'bout bothering them

I purchased a 05 st a little over a year ago. A couple weeks after i had it, i was doing some spirited driving through some canyon roads and the check engine light started blinking, then stayed constant. I took it back to the dealer and they said it was a "random misfire" and reset it.

The light has never come back on, except wen u first turn it on (like it should). So lately ive been trying to resolve some hesitation issues and became curious as to why the check engine light has never come back on. I thought unplugging some things would cause it to come on. so i unplugged the MAF sensor. It started and ran kinda rough but no light. ...unplugged a coilpack. no light.

So now im wondering what does it take to cause the light to come on and is it possible for a dealer to disable it jus so i dont bother them anymore???
How many mile's on your car? When was the fuel filter changed? Ask your dealer for a fuel injector cleaning. I'd add a Steeda SRI or a F/W's CAI, at least!
 

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Anything can be disabled if you know how. I don't know why they would want to however. Get the codes read and see whats up. The codes still reside in the computer even if the light is not on.
 

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change your plugs and don't disable that light unless you want to be back here 6 months later parting your focus out because the engine blew on you
 

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Discussion Starter · #19 ·
yeah, i WANT the check engine light to work properly. i bought it used at a nissan dealr and they pulled a fast one on me and screwed me on an agreement so wen i complained about the check engine light, i figured theyd screw me there too.
when i pulled the sensors, i just idled for a little bit. i ddnt know it took awhile 2 throw the light so thanks for that info.

car has 96000 miles (67k wen i bought it). ive replaced the plugs, wires, fuel filter, and did a custom cold air intake all within the last thousand or so miles. its made the problem less severe...
Posted via FF Mobile <- i hate trying to type this on my phone! lol.
 

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BodyKits=PantiesDrop
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My experience is that the CEL will come on almost instantly if you have a disconnected MAF sensor.
 
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