Different mil mod

[charliex]

this sim doesn't need the original o2 sensor, it generates the signal completely.

narrow band O2 sensors are fairly easy to replicate, wide band on the other hand not so much, the signal of a titania compared to a zirconium is quite different not just amplitude but direction, luckily we don't have to deal with that.

it'll switch lean/rich in closed loop the ecu is looking for both the voltage and the frequency its switching at, the ECU has a preset frequency to cycle the engine so it knows exactly what to look for. the circuit can be adjusted for just about any car, different types of injection, carbs etc will generate a different frequency. As far as i know its not an actual comparison between the two O2 sensors, as it is a base test against a known quantity in the ECU. the frequency determines the cats performance so i dont think it'd need the upstream O2 sensor to compare too, as the working range is already known. (that is as long as the engine is performing correctly, the upstream O2 sensor may alter the base frequency comparison if its out of spec ), it will compare the upstream to the downstream and when the frequencies gets to close it also throws the code, this may explain why some people get it and some don't, as many factors will determine what that base frequency will be.

the OBDII code is thrown when the switching frequency is too high as it then considers the CATs oxygen storage capacity to have detoriated.


blergh i'll rewrite this in the morning, i'm not even making sense to myself

[charliex]

Its a Texas Instruments NE555P

[choi0706]

Originally Posted by eliseowner2b

Any idea how many tanks of gas one of these is going to cost?

I'll find out soon.. just need to test some more along with other testers..

[choi0706]

going towards 400 miles still no light.. he is looking for another test bug, anyone who is interested shoot me a email choi0706@gmail.com

[MikeW]

Originally Posted by choi0706

going towards 400 miles still no light.. he is looking for another test bug, anyone who is interested shoot me a email choi0706@gmail.com

email sent
thanks

[choi0706]

after testing with an official toyota canbus/obdII diagnosic tool this mil mod works.. the ecu is very happy with the signals it's getting..

on a side note, the toyota tool can read all our sensors/test and view them in real or almost real time.. But it's a $4,000 unit..

[charliex]

Good to hear that the circuit is still going strong (for those who want to build their own the circuit diagram is available too )

ddi you try the powertrain settings on the toyota unit ?

[choi0706]

Originally Posted by charliex

ddi you try the powertrain settings on the toyota unit ?

powertrain settings? not sure.. it read the rpms/maf voltages/ o2 values/ etc..

[charliex]

the extended diagnostic data, the rest is just standard obd ii

its unlikely its the same, but worth a shot.

[choi0706]

Originally Posted by charliex

the extended diagnostic data, the rest is just standard obd ii

its unlikely its the same, but worth a shot.

ohh the lotus data? top speed, top rpms? none of that showed up.. but David did say he can reflash toyota ecus with that tool if toyota made a update..

[charliex]

yeah federal modern cars are flashable now, its required by law.

[Bane]

Any update? Has your car triggered the MIL yet?

[Hollywood]

my defouler method seems to work pretty good lately. im getting over 600 miles before it turns on. if it turns on. but the last time it came on it also went off by itself.

[choi0706]

Originally Posted by Bane

Any update? Has your car triggered the MIL yet?

nope.. getting some made for test bugs..

[MikeW]

Originally Posted by Hollywood

my defouler method seems to work pretty good lately. im getting over 600 miles before it turns on. if it turns on. but the last time it came on it also went off by itself.

My antifouler lasted all of maybe 50 miles max before the light came on. I'm mooching an Autoxray to read and clear the codes today.

[Hollywood]

i got my code reader off of ebay for 50 bucks. easy to use and comes in handy sometimes.

[Beanie]

I thought charliex had hacked the ECU -- just some of the data maybe? If you can get to the code that check the post-cat sensor and runs the test for catalytic converter efficiency, that's all you need, right (no hardware mod required)? I mean if you are going to do a hack why not go all the way?

The above description of how the ECU compares the signals matches what I've read about the Toyota ECUs. The test is done periodically after everthing is warmed up. It takes something like 15 minutes (maybe 30? can't recall) of driving before it does the test for the first time.

I have a Power FC and just plugged the post-cat sensor bung. The Power FC is wired for the post-cat sensor, but does not appear to do anything with it. There's an Innovate Motorsports LC-1 in the pre-cat bung, which has two programmable analog outputs (1 narrowband, 1 wideband) plus a digital serial output that I can read via USB to serial converter. LC-1 is like LM1, but cheaper (no gauge). You can buy the gauge for it later, which is what I did. LC-1 consists of the sensor, electronics, and cables and costs $200. The XD-1 gauge can be mounted anywhere. It is very thin (about 1" thick), so you can stick it on just about anywhere. It comes with velcro to stick it wherever as well as screws etc to mount in the dash.


Note: tach goes to 8K, engine goes to 9300. I have another tach (virtual on tablet PC) that goes to 11K.

Even if you can't alter the A/F mixture, it is nice to know what it is.

[edaddy]

Originally Posted by choi0706

going towards 400 miles still no light.. he is looking for another test bug, anyone who is interested shoot me a email choi0706@gmail.com

I'm interested! Email sent...

[Johnny B]

Holy thread resurrection, Batman!