I have the kamikaze and the MIL and it worked perfect. You sure your tapping into the second O2 sensor right? And did u reset the ECU by disconecting the battery for a few minutes? I got a Cel and installed the MIL, reset the ECU, and no cel and its been 6k miles.

 

Yeah. I disconnected the negetive on the battery and it reset, drove for a while, and after about 40 minutes the light came back on. How is the wiring on your MIL? scamatic.

 

http://www.mkiv.com/techarticles/oxy...sor_simulator/

cheap & easy-someone on here has actually built this and it works

 

Another possible solution:

http://www.mazdamp3.com/vbb230/attac...&postid=641867

I'm going to try that if we ever get a warm spell above 30 some degrees so that I can actually get a soldering iron to work!

Later.

Steve

 

Two things,

1st. That circuit is the same one that Kamikaze / Bigjoshracing uses.
2nd. I actually built this circuit with a smaller resisitor (Circuit specifies 1Mohm,. I used 650k)

I'm still throwing a light. This is on a 3G eclipse. The code is P0159 O2 Sensor Slow. After looking at the datalog, I think I might try and only use a resistor on the blue line. The capacitor in the circuit seems to be slowing down the O2 response, and hence throwing a code.

I will let you guys know if I have any luck, and what I find once I have a good solution.

-Brian

 

The capacitor is definitely in there to help filter the signal somewhat. 1uF is pretty big.. so you may just want to keep the cap in but switch to a .1uF just in case. Also.. by going to a smaller resistor you may have made that capacitor look much bigger than it is in the sense of the filter. Since the "cutoff" frequency or characteristic frequency of that circuit is equal to 1/(R*C) then if you lower R you have to lower C as well or you will definitely effect how the output voltage of that configuration varies.

So I'd try to keep the R and C matched to the circuit. Why did you go with a 650k instead of the 1Mohm? Enough people have had the MIL work and so forth that I don't see a big reason to tamper with it. But if you have a reason/knowledge as to why please share as it is of benefit to all of us!

Later.

Steve

 

The 1Mohm was giving a fairly low voltage reading. I was originally under the impression that the ECU keeps throwing codes because the delta between the front and rear sensors was too high.

A person on a dodge message board had built one of these with a 650k resistor, so I figured I would give this a shot.

Also, there is another member on eclipseforums.org (with the same car, same header, same mil eliminator, and same P0159 code) that is experiencing the same problem as I. I guess our ECUs are just a little more sensitive for some reason.

I understand the reason for the capacitor, however in looking at the data log, it appears that the only thing the capacitor is doing IS filtering the response data. I think using a much smaller size resistor (have not determined the value yet), and no capacitor at all, will be the best.

Goal is to drop voltage by about 0.20v. (Readings should be about the same between front and rear with no cat, I'd like to see the rear about 0.20v lower than the front).

I may resort to using a potentiometer on the blue line coming from the O2 sensor and turning it until I see the desired voltage on my datalogger.

-Brian

 

Sounds like you have it covered. So hopefully it works. I plan on building my own MIL for my Lancer based off that diagram and see if it works. I'll post once I get a chance to do it. But good luck sorting out yours! I'd give it a try as recommended by the diagrams though just to see.. at this point it shouldn't be too hard for you to be switching stuff all the time. Remember too if the filter is acting on the voltage.. it will fade it down somewhat... so switching resistors may not get you quite where you want... the filter may give a stepped response that is important for it.. so who knows.

Later

Steve

 

I put a resistor inline last night. (Well actually a few resistors in parallel, since by the time I got around to doing this, any decent parts store was closed, so I put a bunch in parallel to lower the resistance).

The total resistance value was 92.3kohms.

Closest 'RadioShack' value would be about 100k. The resistor was spliced into the blue line, with no other wires altered in the final setup.

Voltage drop appears to be about 0.2 to 0.3 volts. I'm waiting for the SES light. I will keep you guys updated if I get one.

-Brian

(4G64 2003 Eclipse GS)

 

I tried the 1Mohm with the 1uf circuit (the same as the bigjosh)... no go on that. Got a MIL after 100 miles.

Pulled out the 1uf cap out of the circuit... same result after 100 miles.

Tried measuring the voltage.. it's not possible as it is actually pulsed and bounces all over the place and I dont' have easy access to a scope to check it out. But based off my best guesses from what I saw I think I need to knock my value down to 300K to get what I need voltages wise or something. I'll let you guys know if that works..

I did find a bunch of info online that basically states that the sensor is cycled and will go back and forth between about .4V and 1.2V and shouldnt' ever exceed that. I'm guessing that it is just getting thrown too high. I'll find out what code I have right now with a scanner.. but the one I had with the full circuit was "O2 reponse slow"

I'll update you as I go.

Later.

Steve

 

My results were obtained using 7 x 649kohm resistors in parallel on the voltage return line only. I have no capacitor in my setup, and my datalogs look nice and clean, with the second O2 sensor following the first almost exactly. As previously stated 92.3kohm was my final resistance with a voltage drop off of about 0.2-0.3v. (At 0.9, showing more like 0.6-0.7).

I should note that someone on the eclipseforums.org (national boards) tried this with a 100k ohm resistor and he still threw a light. I am unsure of if this was the same code at this point.

The capacitor in the MIL eliminator causes some slowness problems as it must saturate before releasing voltage, also, the 1 Mohm resistor in the original MIL design causes too much of a voltage drop. (at 0.9v it'll put out more like 0.2-0.3v).

-Brian

 

when you say voltage return line... blue or white??? since the black wires are the heater wires.

I got about .6v drop as best as I could measure with the 1M hence I'm going to try a 300K as by my calculations that will get me about a .2 to .3 drop as best as I can measure.

 

The blue line as posted above.

Also remember that how resistance affects voltage drop is a function of current draw (amperage).

It's rather complex to figure it out because the O2 sensor itself is a load (resistance), and the ECU is what controls the current draw.

The best thing I could tell you to do, if you want to tinker with it, is to get a decent size potentiometer that can tune from 0 to 150kohms and put it inline on the blue line.

If you can get a datalogging cable, it would be rather helpful so that you could see what the front O2 sensor is doing as well.

-Brian

 

Please correct me if I'm wrong but:

Everyone is saying they're gonna rip out their header's, put stock back on, and go turbo. As far as I know, I was under the impression you have to go headers/high flo cat with any turbo or sds system because of backpressure created by the stock setup. Exhaust has to keep up with FI. Like I said, someone correct me if I wrong, but the headers are a necessity. I believe rrm and kamikaze needs to come up with a mil elimanator that's not half-assed, people shouldn't live with "just leave the cel on, who cares" just a thought though.

 

I'm an electrical engineer... so I do understand the voltage drop and so forth . I don't have datalogging capabilities right now so yeah that is making my life a bit harder.

I did let it run and check it with a meter. The meter response wasn't fantastic but I got readings bouncing from .1 to .6V's Which leads me to believe it is an oscillating signal in some form or whatever. So assuming that .6V is more or less the peak that I am seeing/exists You can work back and determine the current flow from the drop across the known resistance. Then yes you compensate for what the resistance of the sensor will be and can arrive back.

I'm getting an impression that the Lancer may need a different value, but I will see. I need to sell the car soon but want to leave the header on so I'm trying to fix the issue that way.

now as far as Jaymz...

Yes you do typically want some form of higher performance header and exhaust as they are considerable restrictions to a turbo. So... yeah that's why I'm working hard at this fix as well is to try and figure out a way to get it to work for you guys too.

I'll try it again tonight and I'll update you when I get some results.

Later.

Steve