Front O2 sensor limit

root · **Joined:** Fri Dec 22, 2006 8:42 pm **Posts:** 51

I just logged in RomRaider to see if the StreetTuner logger was the cause of the limiting. I couldn't log the LM-1. The goal was just to see if we still hit a brick wall. And I did. I logged the sensor #1 AFR and current. The AFR stopped at 11.02 and the current stopped at -1.38.

And, fwiw, based on my table, -1.38 should interpolate to roughly 10.98.

LGT-3-6 · **Joined:** Wed May 24, 2006 8:11 pm **Posts:** 205

Jon [in CT] wrote:

LGT-3-6 wrote:

Only works on OpenPort < 1.3 AFAIK

It should work with OpenPort 1.3. Maybe you weren't trying to also log an Innovative product at the same time? If you weren't, then the Logworks logger won't work, according to Klaus Allmendinger (Innovative's chief engineering honcho) in this post: http://www.innovatemotorsports.com/forums/showpost.php?p=31941&postcount=8. If your OpenPort 1.3 didn't work and you were also logging an LM-1 or LC-1, then I suggest you register at Innovative's forums and revive that thread to report the problem.

Nope, apparently there's some timing issue that causes problems speaking OBD2. I've tried various other OBD2 packages that are _supposed_ to work with this cable as well, won't communicate properly. This I believe was confirmed by someone over at openecu, someone else posted to question before I did. But perhaps I should try the newer drivers!!!

merchgod · **Joined:** Wed Mar 29, 2006 10:38 pm **Posts:** 5336

root wrote:

I just logged in RomRaider to see if the StreetTuner logger was the cause of the limiting. I couldn't log the LM-1. The goal was just to see if we still hit a brick wall. And I did. I logged the sensor #1 AFR and current. The AFR stopped at 11.02 and the current stopped at -1.38.

And, fwiw, based on my table, -1.38 should interpolate to roughly 10.98.

I would pull your ROM with Ecuflash and make sure your changes were actually made. There's no limit for "a/f sensor #1 lambda" other than that which is already defined.

LGT-3-6 · **Joined:** Wed May 24, 2006 8:11 pm **Posts:** 205

merchgod wrote:

root wrote:

I just logged in RomRaider to see if the StreetTuner logger was the cause of the limiting. I couldn't log the LM-1. The goal was just to see if we still hit a brick wall. And I did. I logged the sensor #1 AFR and current. The AFR stopped at 11.02 and the current stopped at -1.38.

And, fwiw, based on my table, -1.38 should interpolate to roughly 10.98.

I would pull your ROM with Ecuflash and make sure your changes were actually made. There's no limit for "a/f sensor #1 lambda" other than that which is already defined.

I saw the same limit. although it wasn't clear if it was both the sensor current and AFR that was limited.

LGT-3-6 · **Joined:** Wed May 24, 2006 8:11 pm **Posts:** 205

root wrote:

I just logged in RomRaider to see if the StreetTuner logger was the cause of the limiting. I couldn't log the LM-1. The goal was just to see if we still hit a brick wall. And I did. I logged the sensor #1 AFR and current. The AFR stopped at 11.02 and the current stopped at -1.38.

And, fwiw, based on my table, -1.38 should interpolate to roughly 10.98.

st logging has issues, unfortunately. I wouldn't recommend it.

root · **Joined:** Fri Dec 22, 2006 8:42 pm **Posts:** 51

merchgod wrote:

I would pull your ROM with Ecuflash and make sure your changes were actually made. There's no limit for "a/f sensor #1 lambda" other than that which is already defined.

Aye. I will do that tomorrow.

root · **Joined:** Fri Dec 22, 2006 8:42 pm **Posts:** 51

LGT-3-6 wrote:

st logging has issues, unfortunately. I wouldn't recommend it.

Not sure what the relevance of that statement is. I've used it for a long time and it has functioned fine. And I've also shown that it isn't the cause of the brick wall, as I logged the same in RomRaider.

We'll see when I pull my ROM if the changes were written. If not, I'll try again. If it is still an issue, we'll research some more.

LGT-3-6 · **Joined:** Wed May 24, 2006 8:11 pm **Posts:** 205

root wrote:

LGT-3-6 wrote:

st logging has issues, unfortunately. I wouldn't recommend it.

Not sure what the relevance of that statement is. I've used it for a long time and it has functioned fine. And I've also shown that it isn't the cause of the brick wall, as I logged the same in RomRaider.

We'll see when I pull my ROM if the changes were written. If not, I'll try again. If it is still an issue, we'll research some more.

It's hard to use the data if there are random points in there that are just wrong. I know romraider does this occasionally, but it seems more common in ST, lots of values that are repeated that obviously shouldn't be, some numbers that are randomly just slightly high or low, when you know they really weren't. Also MAF readings of 650, etc. Also calculated load seems to read high for some reason?

But I digress.

merchgod · **Joined:** Wed Mar 29, 2006 10:38 pm **Posts:** 5336

Ok, the reason, in the example given, that "A/F Sensor #1" logs as 11.02 at -1.38mA is because the resolution of this standard SSM parameter is not good enough. The next richest AFR that can be displayed is 10.91. Note, this is a limitation of Subaru's logging parameter, not the value as used by the ECU. I'll be adding an "A/F Sensor #1 (Direct)" in the next logger update.

root · **Joined:** Fri Dec 22, 2006 8:42 pm **Posts:** 51

merchgod wrote:

Ok, the reason, in the example given, that "A/F Sensor #1" logs as 11.02 at -1.38mA is because the resolution of this standard SSM parameter is not good enough. The next richest AFR that can be displayed is 10.91. Note, this is a limitation of Subaru's logging parameter, not the value as used by the ECU. I'll be adding an "A/F Sensor #1 (Direct)" in the next logger update.

Cool. Thanks for looking into it. Do you know if the sensor current logging is suffering from the same issue? Or is -1.38 possibly the lowest the ECU will actually read and convert (or the lowest the sensor itself can achieve), and thus an AFR of ~10.98 will still ultimately be the low end cap?

FWIW, I just pulled my ROM and checked to make sure my changes had been written. They were.

merchgod · **Joined:** Wed Mar 29, 2006 10:38 pm **Posts:** 5336

root wrote:

merchgod wrote:

Ok, the reason, in the example given, that "A/F Sensor #1" logs as 11.02 at -1.38mA is because the resolution of this standard SSM parameter is not good enough. The next richest AFR that can be displayed is 10.91. Note, this is a limitation of Subaru's logging parameter, not the value as used by the ECU. I'll be adding an "A/F Sensor #1 (Direct)" in the next logger update.

Cool. Thanks for looking into it. Do you know if the sensor current logging is suffering from the same issue? Or is -1.38 possibly the lowest the ECU will actually read and convert (or the lowest the sensor itself can achieve), and thus an AFR of ~10.98 will still ultimately be the low end cap?

FWIW, I just pulled my ROM and checked to make sure my changes had been written. They were.

Each unit increment/decrement for "A/F Sensor #1 Current", as far as logging is concerned, is 0.125mA. The logging parameter itself is not limited to anything near -1.38mA on the low end. I do not know what the mechanical limitation of the sensor itself is.

root · **Joined:** Fri Dec 22, 2006 8:42 pm **Posts:** 51

merchgod wrote:

Each unit increment/decrement for "A/F Sensor #1 Current", as far as logging is concerned, is 0.125mA. The logging parameter itself is not limited to anything near -1.38mA on the low end. I do not know what the mechanical limitation of the sensor itself is.

OK. I was definitely pegging -1.38mA. Which means there is a chance we aren't going to be able to get below 10.98 AFR (or whatever the correctly scaled value would be) even with the direct logging update.

Unless, per chance, there is another table or value or something along the path to the current that has a floor in it.

merchgod · **Joined:** Wed Mar 29, 2006 10:38 pm **Posts:** 5336

root wrote:

Unless, per chance, there is another table or value or something along the path to the current that has a floor in it.

I haven't checked for a limit to current yet.

Jon [in CT] · **Posted:** Wed Apr 09, 2008 4:03 pm

merchgod wrote:

root wrote:

Unless, per chance, there is another table or value or something along the path to the current that has a floor in it.

I haven't checked for a limit to current yet.

"Current" might be limited by a voltage-to-current translation table. That is, voltage might be lower than the leftmost entry in the table but current will be limited to its leftmost entry.

root · **Joined:** Fri Dec 22, 2006 8:42 pm **Posts:** 51

FWIW, I just recorded a 10.91 AFR in the logger. Unfortunately I wasn't logging current as well at the time, so I have no idea what it would have said. I also have absolutely no idea how close to accurate the 10.91 was since my wideband wasn't logging.

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