Downside to MIL Eliminator?

[mazdaowner123]

Hey, I was just wondering if there was a downside to running an MIL eliminator. Someone mentioned that since it is tricking the o2 sensor, it is messing with the amount of fuel the car is throwing in and can mess stuff up. Anyone have any input on this?

~brian

 

[PhreakV]

well one thing could be that if something is truly wrong with your a/f your car won't know to dump/add fuel or to let you know through the CEL...

 

[Captain KRM P5]

the first o2 sensor is what cooperates with the ECU to correct/tune the air and fuel ratios for the car. a MIL eliminator goes on the second o2 sensor that comes after the first catalytic convertor. all that sensor does is tell the ECU if the cat has been removed or is malfunctioning via different temperatures triggering different voltages on that second sensor. if the first cat is removed, the exhaust temp is going to cause the sensor to send a signal to the ECU showing that it is gone, but it does not tune the car. All a MIL eliminator really is is a bundle of wires and resistors that change the voltage sent to the ECU by that second sensor to make the ECU think the emissions system has not been modified.

Using OBD2 scantool software shows to me that the range of voltage the second o2 sensor is capable of putting out seems really limited, moreso than the first sensor. This leads me to think that the second sensor is more of a very low tech watchdog than a sensor, in place to make sure you aren't smoggin up the skies

 

[Dr.Sound]

very good, informative repply, Captain.

thanks you.

 

[mazdaowner123]

Yes, thank you very much captain, that was very helpful.

~brian

 

[KyRaceFan]

ive got an unused apex MIL elim for sale if you need one.

[/shameless plug]

 

[BOOSTR]

"This leads me to think that the second sensor is more of a very low tech watchdog than a sensor, in place to make sure you aren't smoggin up the skies "


I am currently running a 2.5 catless downpipe and no MIL eliminator on my MSP. Have over 6,000 miles since the install, never got any CEL's.

I don't think that you need to hack in to your wiring. At least thats my experience. The MSP runs pig rich, with or without cats! Just look at your muffler tip if you do not believe me. I have seen no increase or decrease in the amount of carbon soot in the tip.

 

[Captain KRM P5]

you are the first and only case I have ever heard of not throwing a CEL from removing a cat on these cars, and i've removed more than a few myself weird

"This leads me to think that the second sensor is more of a very low tech watchdog than a sensor, in place to make sure you aren't smoggin up the skies "


I am currently running a 2.5 catless downpipe and no MIL eliminator on my MSP. Have over 6,000 miles since the install, never got any CEL's.

I don't think that you need to hack in to your wiring. At least thats my experience. The MSP runs pig rich, with or without cats! Just look at your muffler tip if you do not believe me. I have seen no increase or decrease in the amount of carbon soot in the tip.

 

[BOOSTR]

I have heard about others not using them either. It is wierd, but it is in fact the case. The miles keep on turning and no cel ever, with the OEM wiring in the 2.5 downpipe.

 

[MSPinVA]

your and their 02 sensors are probably too gunked up to throw a CEL, or defective. Eh, either way it saves you the trouble of soldering an MIL elim in

 

[SoniCraze]

i threw a cel with no cats....ive heard of people using a adapter to recess the mid further away from the "flow" and not throwing a cel...something about a spark plug adapter.

 

[Glowmunkey]

Mine threw a code too...

And FYI, O2 sensors create voltage by oxygen content, not temperature.

 

[BlkZoomZoom]

The recessing of the O2 works quite well....If you read the activity of my rear O2 it stays at a steady .6v's