This is topic Question about MIL Eliminators...Engine in "SAFE MODE" in forum Tech Talk at Northern California Ford Owners  .


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Posted by 98StangPower (Member # 518) on :
 
if you have a offroad h pipe and your car has the check engine light on, does it tell the computer to run in "safe mode" and not properly mix the air to fuel ratio...or something like that?
 

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Posted by Quick 88LX (Member # 1950) on :
 
well, from what I know, all the check engine light does is annoy the driver until they fix the problem and make the light go away. Other than that, all the light is telling you and your cars computer is what it is detecting as a problem. So when your light comes on, it not only is telling YOU there is a problem, but it is also telling your computer there is a problem for future diagnostics. But if YOU KNOW the light is on because you installed an off road h pipe or something liek that, then don't worry about it unless that orange light really does bother you. Or get some MIL eliminators
 

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Posted by Black94 5.0 (Member # 655) on :
 

quote:

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Originally posted by 98StangPower:
if you have a offroad h pipe and your car has the check engine light on, does it tell the computer to run in "safe mode" and not properly mix the air to fuel ratio...or something like that?

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YES your car does run in safe mode if the "Malfuncition Indicator Light"(MIL) is on...
This is especially true in 96+ cars...96+ cars have OBD II computers, OBD II computers were developed to keep up with the strict smog laws...When your engine is in safe mode it retards timming and changes other veribles(which limit horse-power) becuase it does not have the information to give it peak performance(Example:Bad O2 signal with an "off-road H-pipe")....

OBD II cars have four O2's..The reason for this is to detect a malfuntioning catlytic converter..
One O2 is located infront(upstream) of the "cat" and one is located behind(downstream)of the "cat"..When you remove the cat the O2's tell the computer that something is wrong with the cats..

Thats why you need MIL eliminators...
 

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Posted by 98StangPower (Member # 518) on :
 

quote:

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Originally posted by Black94 5.0:

quote:

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Originally posted by 98StangPower:
if you have a offroad h pipe and your car has the check engine light on, does it tell the computer to run in "safe mode" and not properly mix the air to fuel ratio...or something like that?

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YES your car does run in safe mode if the "Malfuncition Indicator Light"(MIL) is on...
This is especially true in 96+ cars...96+ cars have OBD II computers, OBD II computers were developed to keep up with the strict smog laws...When your engine is in safe mode it retards timming and changes other veribles(which limit horse-power) becuase it does not have the information to give it peak performance(Example:Bad O2 signal with an "off-road H-pipe")....

OBD II cars have four O2's..The reason for this is to detect a malfuntioning catlytic converter..
One O2 is located infront(upstream) of the "cat" and one is located behind(downstream)of the "cat"..When you remove the cat the O2's tell the computer that something is wrong with the cats..

Thats why you need MIL eliminators...

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The MILs are placed on the front or the rear O2 sensors?

Thanx for the info.

[ February 17, 2003, 05:24 AM: Message edited by: 98StangPower ]
 

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Posted by Quick 88LX (Member # 1950) on :
 
In the rear. When you buy them, the instructions even say IN BOLD to put them in the rear. That will solve all your problems my man
 

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Posted by 98StangPower (Member # 518) on :
 

quote:

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Originally posted by Quick 88LX:
In the rear. When you buy them, the instructions even say IN BOLD to put them in the rear. That will solve all your problems my man

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I didnt get any instructions with mine... But thanx for letting me know they go on the back.
 

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Posted by punkrawkdude99 (Member # 2427) on :
 
95% of the time check engine light comes on due to an emissions problem
 

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Posted by cobraracer46 (Member # 1142) on :
 
No, your mustang will not run in safe mode when the MIL light is on for anything except an over temp condition. My MIl light comes on occasionally because I have not had the time to make some MIL eliminators, but the light coming on is no big deal for me, I just turn the light off. I don't feel any performance diffrence what so ever when my light comes on. your mustang will run in safe mode only when the PCM detects an engine over temp condition. Basically what happens is that the PCM will cut out every other cylinder so some cylinders can pump in air and cool down the motor..
 

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Posted by Black94 5.0 (Member # 655) on :
 

quote:

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Originally posted by cobraracer46:
No, your mustang will not run in safe mode when the MIL light is on for anything except an over temp condition. My MIl light comes on occasionally because I have not had the time to make some MIL eliminators, but the light coming on is no big deal for me, I just turn the light off. I don't feel any performance diffrence what so ever when my light comes on. your mustang will run in safe mode only when the PCM detects an engine over temp condition. Basically what happens is that the PCM will cut out every other cylinder so some cylinders can pump in air and cool down the motor..

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quote:

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Originally posted by cobraracer46:
The car will run just fine with a cat effiency code. I know for a fact, my 01 Cobra runs the same when the check engine light comes on because the PCM detected a cat failure. The PCM uses the front o2 sensors for fuel trim, not the rears. The rear o2 sensors are only used to monitor the cat converter effiency.

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quote:

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Originally posted by Black94 5.0:
Why would you run your car with the MIL light on?....Arent you worried that it might be on for some reason other than the O2's?...

How long have you had your MIL on for, before you reset it??.....When an OBD II computer has a MIL on for a while, I'm 99% positive it goes into "safe mode"..Maybe your MIL was not on long enough...[/QB]

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I have the exact same scan tool that Ford dealers use, so when my light comes on, I know what it is for. The longest time I let the MIL light shine was 1 full day. I think I will finnaly get around to making my MIL eliminators this weekend.
 

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Posted by 98StangPower (Member # 518) on :
 

quote:

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Originally posted by Teddy Tiger:
How about a pair of decent high flow cats?

Nick

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