why do you think that our ECU is incapable of controlling a wideband? i can definitely see lots of variables in o2 sensor control subroutine, many not-so-known, i bet there can easily be ampere readings off that sensor among those. have you done disassembly of that part and compared values with amperemeter?

 

I want my $5.

 

so you're saying you think you can add code to the current rom's we use and make the stock ecu function with a wideband connected directly to the stock front o2 sensor plug?

im not saying it cant be done.. im saying that as is the ecu cant control a wideband o2 sensor.. and how much more space is left on the flashchip on our ecu? and what about the excessive memory and cpu usage this new process would take up? can the stock ecu even handle something like that?

theres to many variables to just say you can alter code and make it just work.. its going to use more resources within the ecu and etc.

 

i think that the ecu is already doing this. rom and cpu is probably no issue here.
what about MUT requests 3D/3E, anyone logged it?

anyway, i need someone who knows front o2 subroutine.


dude, go race a subie.

 

I'll show this to Roadspike on monday and see what he says. hes actively always looking up subroutines in the roms and knows his way around the code pretty well. personally i never even looked at the code, and i haven't messed with coding since 8 yrs ago with C in freebsd when i used to make custom code for ircd's (s_err.c etc).. i am of no help at all pretty much.

im 99% sure Roadspike can help justastockevo

 

A wideband Bosch LSU4.2 has 6 wires. You need to connect them to the ecu.
we have just 2 ports for lambda stuff. one heater and one signal (voltage)

A Wideband gives a current to the ecu, witch is relative to the lambda value. We can only measure a voltage 0-5v. no current input in the ecu, that is hadware design.

A Wideband measures the exhaust temperatur. A Narrowband not.

A Wideband needs a static temperatur (about 600-750 degC), the heater is switched on and offby the ecu. it depends on the exhaust temperatur.

Evo 1-9 does not have anything for a wideband in the sourece code.
Maybe the X's have some code, i haven't see the code for them.

I have replaced some hundret o2 sensor on mitsubishi over the years, i have never seen a wideband sensor, all 0-1V narrowband. this is verified by oscilloscope.

 

What the h3ck is the goal here?

Imagine that you can rewrite the code so the ECU accepts a wide-band's input. That's complete and utter over-kill for setting the fuel trims. Or are you actually thinking of not having an open-loop mode at all? Are you actually thinking of reworking all of the code (again, assuming that such is possible) so you remain in closed-loop at WOT?

On the other hand, if all you want is to log your AFRs, then just attach a PC or other logging device to the output from the LC1. That's what it's for.

On the third hand, if what you're trying to do is tune the car (by which I mean alter the open-loop maps), then you don't need to log at all (although I would if you could). You just need to install the wide-band, attach a gauge, and have at it.

What's goal here?

 

subaru oem sensor, 4 wire (quite similar to ours), which is controlled by the subaru's ecu (both sh4) produces very similar results to Bosch LSU 4.2, which has 5 wires. heater and sensor control, judging by wiring diagrams, are quite similar to what we have in our cars. even if our factory sensor does not have that capability, if we can log current from that circuit then we can install subaru's replacement denso sensor and enjoy wideband logging, without a wideband controller.

 

we can probably be of more control if we know how exactly our ECU processes o2 sensor data. better trim controls, better/easier logging, it all adds up.

 

Maybe, but I doubt it.

As I said above, wide-band-quality data (if you now accept that wide-bands provide more precise information) is over-kill for setting the fuel trims. I can't see any gains there and, of course, this has little to do with performance ... it's really just fuel economy.

As to logging, I suppose getting the ECU to act as a wide-band controlled means you could log the AFR more precisely via the ECU, but my guess is that it'll take more time and money to convert our ECU to wide-band than it would take to just use a stand-alone wide-band controller (which, I believe, you already own). To the extent that logging only the ECU is easier than logging the ECU and a separate wide-band value, OK, I sort of see your point, but I have a different definition of "easier" in that mine doesn't involve a complete reworking of the front O2 sensor's circuit.

Better control if we understand exactly how our ECU works? Total agreement. But before you hack apart your ECU, maybe some more reading on the differences between narrow- and wide-band O2 sensors is in order. I would, personally, start from a decent understanding of the stock system before planning some changes. And if you're still holding onto the idea that any O2 sensor with a certain number of wires is interchangeable, then you're not there, yet.

 

Narrow bands are just used as a cheap alternative to monitor that the car is at the very narrow stoichiometric range of 14.7 and up to 15.xx or near there. they are not designed for HP engines like a wideband which is considered "laboratory Grade" . From my research over the past few months learning about tuning ECU's I read that originally WBO2's were in the thousands of dollars and only used by the factory to set up the original ECU's. WB's output a current vs Straight Voltage, and as mentioned earlier heat will kill a WB and are only accurate at low heat range and should be kept under 800-900 degrees .

here is some info from the AEM manual.

Because the AEM gauge utilizes the internal AEM UEGO controller and Bosch UEGO Sensor, it is accurate and repeatable to 0.1 of an air/fuel ratio point! With this, there is no abrupt oscillation as found in many competitor gauges, which utilize a narrow band oxygen sensor detecting only stoichiometry.


Typical production vehicle oxygen sensors rely on “Nernst Cell” technology, commonly called “Narrow Band” and sometimes erroneously described as “Wide Band”. This is a very cost effective method that outputs a voltage based on the oxygen content of the gas being sampled. It is accurate in the region surrounding stoichiometric operation and leaner. Unfortunately, in the rich region where high performance engines usually operate, their accuracy and repeatability is virtually non-existent.

See attached image.

The rich region output of narrow band O2 sensors is temperature dependant, which renders it useless if an accuracy better than 1.5:1 AFR is desired. This is immediately obvious given the fact that a single output voltage actually represents wildly different air fuel ratios depending on the unregulated and unmeasured sensor temperature. These sensors were designed for operating closed loop around stoichiometry (14.64:1 for gasoline), and for performance tuning they are useless.
The heart of the AEM gauge is the Bosch LSU4.2 Universal Exhaust Gas Oxygen (UEGO) sensor. This type of sensor is commonly referred to as “laboratory grade” and works on a different principle than the narrow band oxygen sensor found in most Page 2
vehicles. Its unique design makes precision AFR measurements possible over the entire operating range.
UEGO sensors use a “current pump” to determine the actual oxygen concentration within the sensing element or. The output is in the form of a very small current, which varies depending on the air-fuel ratio. This is completely different from a narrow band oxygen sensor, which directly outputs a voltage. The UEGO sensor design allows measurement of the exact air fuel ratio over the entire operating range.

So narrow bands just do not give you the accuracy needed to tune the AF ratio. It only reads in a NARROW BAND unlike a Wide Band which has a higher resolution and will read in the rich range. So there is nothing you can do to make the mechanics of the NB work for tuning in an ECU. They are not accurate and only used to let you know if something is out of Stoichiometric and turn on the CEL to have the car checked out incase something is wrong.

Do a search for WB and you'll find numerous links to tuning forums of almost every car make out there.

Athanasios


Athanasios

 

at this moment, i don't want anyone to tell me the difference between a narrow and a wide band sensors, sensor voltage, 0-1v, 0-5v, post that narrowband graph, quotes from wideband controller manufacturers, etc. i knew that for some last 5 years. now i want to know something else, not something readily available on google.

i need to find out if current of the factory o2 sensor wire can be logged with our ECU. thank you.

 

No.
Logging voltage is a feature every microchip has build in.
To log current you need a different board design. Or a special Microchip that translates the current signal to a voltage signal.

Our Ecus just understand voltage signals.
You can build you own circuit for translation, but thats a wideband controller like innovat or AEM.

 

is subie's board completely different in that regard? i just want to make sure.

 

here's a quote from another forum thread:

full thread:

https://www.evolutionm.net/forums/ec...res-how-6.html

so common wisdom goes that at least our o2 heater is checked for current via ECU (and throws CELs if things go wrong), will you agree on that? what is that made you actually think that our ECU can't read the o2 sensor ampere rating? please let me know the details if you know more.