Anyone heard of these??? Supposedly you use them if you have a high flow cat so that you don't pull a check engine light. I have only seen them for Mustangs and wondered if I need one with my new high flow cat that was installed on my car.
www.mileliminators.com

if your CEL isn't on, you don't need one.

JWT has a resister program that tells your ECU to ignore your rear O2 sensor, if thats what you mean?

Do all JWT ECU's have this resistor program? Reason I ask is that I have a JWT ECU for my BB DET and It pulled a rear O2 sensor malfunction code.

i had to ask for it on mine. they put a resister for the rear O2 sensor and the EGR.

They want 100bucks to wire in that resistor for my car since I switched ecus (96200sx SE-R has different rear o2 sensor than 99SE-L)

anyone know the resistance value for this resistor ?

yes, what resistor should we get and which wire do we splice it into?

if you dont know the value, just tell us what color bands are on the resistor, please...

I think the resistor is not actually located on the wire on the o2 sensor but inside the ecu. Not saying that you couldn't look at the ecu layout of 2 ecu's one with the resistor soldred in and one without, but it could be difficult.

hmmm...this is interesting....could it be that a 5 cent resistor can be wired into the o2 sensor...bypassing the mil light ?..i might just have to experiment with different values...and bust out the digital multimeter...

Exactly what I was thinking, but as you know the voltage that comes from the o2 sensor wire is variable and also not a linear function. What you would basically have to do is find a resistor that would keep the ecu reading not too low a voltage.

I'm sure you can find more information online.

what do you think about using a potentiometer to variate the info to the ecu ?

Here's what I'm thinking, meaning don't take it as complete truth..

The thing that modulates is the O2 sensor signal. Since as far as I know you adjust the potentiometer manually you would have find a way to modulate it at the time the ECM requires it.

According to the FSM for my 97 the output voltage of the sensor is from 0 to 2.2V. Also a properly functioning REAR o2 sensor is when
<fsm rant>
"racing up to 4,000 rpms under no load at least 10 times... the voltage should be .6v and under .55v at least one during this procedure. or during coasting from 50mph in 3rd gear voltage should be above .6v and below .55v at least once." </end fsm rant>

The rear o2 sensor has 3 wires, white( sensor) , red/yellow(sensor heater), black( ground).

The ECM checks the white sensor signal voltage and also the positive heater wire. One of the checks for a good o2 heater sensor is a resistance of 5.4 - 6.7 ohms between the ground heater wire and the positive heater wire.

I'm not sure what happens when you remove the cat, I'm assuming the o2 sensor heats up more therefore throwing too low a voltage to the ECM, maybe an amplifier is needed ?

Any ideas appreciated. It would be great to not have an MIL light when running a test pipe.

This is a great link, with a nice schematic and explanation.
http://www.zx2racing.com/mods/mods_mil.htm

A resistor ain't gonna cut it. Per the FSM its flip, flop, flip, flop.

You need a 555 circuit like this.....O2 simulator (http://jdmfan.com/technical/performance/o2sensor_simulator/) .... Your resistors may vary :D

Cheers,
Charlie :)

Tune in next week when we build a turbo timer with a $10 Velleman kit!

thats why I like this board, teamwork at its best....:cool:

Cool as sh*t. We have the schematics for an o2 sensor signal modification and also one for an o2 sensor emulator.

Time to go to Radio Shack...

Well, thanks for the info on this thread. Now I need one of these simulators. Anyone gonna make one? If you do make me one and I pay you for it. If so send me a pm.

Well I just got off the phone with JWT and the guy was real nice... He stated that all they do to eliminte the rear o2 sensor is solder in a reistor onto the board and he was nice enough to devulge the values.. guess what it is?? 44K ohms.. he dident state which wire to wire it up on but i this has been answered here.. have fun. this will be my mod for this weekend..