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[skippy]

Has anyone herd of removing 02 sensors ,  I read an article about this ,that Speeds Preformance had a way to download a program to thick the ecm  to think they are still in use  but they remove them and plug the bungs  I think I like this idea any thoughts good or bad tks .....

[Twolanerider]

Has anyone herd of removing 02 sensors ,  I read an article about this ,that Speeds Preformance had a way to download a program to thick the ecm  to think they are still in use  but they remove them and plug the bungs  I think I like this idea any thoughts good or bad tks .....

They are used to such a minimal extent in stock trim, and they supply such a relatively small amount of information that they are only a little better than not there to begin with  .

[RedDevil]

They are used to such a minimal extent in stock trim, and they supply such a relatively small amount of information that they are only a little better than not there to begin with  .

My understanding of them is they have a very limited amount of auto adjustment range for your AFR, vice using the wideband sensor with an ECM that uses them (such as the ThunderMaxx).  Would you notice anything by plugging the bungs and fooling the ECM into thinking they were there?  Probably not.  But with the pipe manufacturers putting the bungs on their new pipes and if you keep your stock ECM and either SERT it or something similar, why would you take them off?  Just curious.  I'm not saying my way was right, but I left them on with my stock ECM and SERT map.
Cheers ,
Red

[Chief]

I don't see how removing them and installing a device, like the Power Commander sensor eliminators, could be bad. All the eliminators do is pass a constant voltage to the ECM instead of the actual feedback from the 02 sensor. This way, the ECM never gets any indication that it needs to do anything to lean it out. It's just status quo all the time.

As I understand it all, the only reason they are there is so the factory can use an ECM that will continue to lean out the mixture until the sensor tells it to stop. This, all because the EPA is all over their back to clean up the emissions. They are not a performance tuning device, but only an emissions reduction device.

I have eliminated them on my bike with the PC eliminators, and the bike runs great.

The only benefit I see to the factory using the narrowband sensors, is that the factory bungs are already in the pipes so I don't have to add them for any sensors I need to install.

[ultrafxr]

My understanding of them is they have a very limited amount of auto adjustment range for your AFR, vice using the wideband sensor with an ECM that uses them (such as the ThunderMaxx).  Would you notice anything by plugging the bungs and fooling the ECM into thinking they were there?  Probably not.  But with the pipe manufacturers putting the bungs on their new pipes and if you keep your stock ECM and either SERT it or something similar, why would you take them off?  Just curious.  I'm not saying my way was right, but I left them on with my stock ECM and SERT map.
Cheers ,
Red

Does your new map have the ability to control the afr when the system does go into closed loop?  Or does the afr in closed loop mode revert back to what the factory put in there?   Haven't seen latest sert software / map so no sure how all this will work with the O2 sensors left in place.  I know that with the PCIII you install O2 eliminators so the ecm is "satisfied" when it would otherwise go into closed loop mode and affect the afr. 

[Chief]

Does your new map have the ability to control the afr when the system does go into closed loop?  Or does the afr in closed loop mode revert back to what the factory put in there?   Haven't seen latest sert software / map so no sure how all this will work with the O2 sensors left in place.  I know that with the PCIII you install O2 eliminators so the ecm is "satisfied" when it would otherwise go into closed loop mode and affect the afr. 

That's why I would be using the eliminators, just so this isn't a question. This unkonwn AFR adjustment just adds another layer of complexity to the puzzle. Using the eliminators would simplify the puzzle by taking the sensors out of the loop, open or closed. (pun intended)

[Twolanerider]

As I understand it all, the only reason they are there is so the factory can use an ECM that will continue to lean out the mixture until the sensor tells it to stop. This, all because the EPA is all over their back to clean up the emissions. They are not a performance tuning device, but only an emissions reduction device.

True, the stock narrow band sensors don't provide information beyone yes/no.  On top of that there is much (most) of the operating range where the open loop system isn't even active.  The stock systems capability on the 07 really is suprisingly lame.

[kojak]

It was confusing for me! Here is what I learned and why I ended up using the SERT on my 07.
The ECM is only using the O2 sensor feedback signal when the system is in closed loop mode. Closed loop mode occurs only under certain conditions which are light load, steady speed part throttle, constant mode(where most of us spend majority of time on the highway). It is only after these conditions that the  EFI will go into closed loop mode and the ECM will adjust until the O2 crossover point is in the 14.7:1 A/F range. The beauty of the race tuner is that you can adjust the bias (map) to have the closed loop AFR be say 14.2:1 using the feedback from the narrowband sensors (hence the +/-0.5 afr adjustment). Otherwise you are using the programmed map in the ecm or with the PC3, the piggyback adjustments to the base map.

[Hoist!]

It was confusing for me! Here is what I learned and why I ended up using the SERT on my 07.
The ECM is only using the O2 sensor feedback signal when the system is in closed loop mode. Closed loop mode occurs only under certain conditions which are light load, steady speed part throttle, constant mode(where most of us spend majority of time on the highway). It is only after these conditions that the  EFI will go into closed loop mode and the ECM will adjust until the O2 crossover point is in the 14.7:1 A/F range. The beauty of the race tuner is that you can adjust the bias (map) to have the closed loop AFR be say 14.2:1 using the feedback from the narrowband sensors (hence the +/-0.5 afr adjustment). Otherwise you are using the programmed map in the ecm or with the PC3, the piggyback adjustments to the base map.

hey kojak, what's wrong with individual cylinder tuning and AFR at all RPM's, piggybacking the base map? Eliminating the O2 sensors is no great loss with the stock ECM program. This PC system is proven, continually improved, reliable and supports a very wide market, not just HD. No one will ever agree on what to use. But PC's just a different approach. The best thing to understand, as I see it, is to do what the guy who's tuning it recommends. If you trust him, why not? If you don't agree with him, find one you do trust. A good tuner is more important than anything else! Hoist!

[Chief]

It was confusing for me! Here is what I learned and why I ended up using the SERT on my 07.
The ECM is only using the O2 sensor feedback signal when the system is in closed loop mode. Closed loop mode occurs only under certain conditions which are light load, steady speed part throttle, constant mode(where most of us spend majority of time on the highway). It is only after these conditions that the  EFI will go into closed loop mode and the ECM will adjust until the O2 crossover point is in the 14.7:1 A/F range. The beauty of the race tuner is that you can adjust the bias (map) to have the closed loop AFR be say 14.2:1 using the feedback from the narrowband sensors (hence the +/-0.5 afr adjustment). Otherwise you are using the programmed map in the ecm or with the PC3, the piggyback adjustments to the base map.

Kojak,

The problem I have with this theory is that the narrowband sensors work like a light switch, not a dimmer. They only tell the ECM yes or no, nothing in between. The only message the ECM can get is rich for AFR's under 14.7, and lean for AFR's over 14.7, or some other setting, but the point here is that this crossover point is fixed. It can't move.

When the ECM goes into closed loop mode, the ECM keeps checking the feedback voltage from the O2 sensor to see if the sensor says rich or lean. The ECM then starts removing fuel from the injectors until the sensor switches from rich to lean, or true to false, or whatever. The point here is that this switch always occurs at the same point.

In order for it to work as you have described above, the SERT would have to change the crossover point of the sensor, so they would switch from rich to lean at a lower AFR. I don't think that is happening. I don't think the SERT is capable of altering the sensor's crossover point, which means on the road, in closed loop mode, you will wind up right back at the factory lean / EPA compliant 14.7.

In my mind, the use of a narrowband sensor in a closed loop system will always wind up at the same AFR. Otherwise, the sensor is being ignored, and you are not in closed loop mode.

If you could replace the stock narrowband sensor with a different sensor with a lower AFR crossover, then you could use the part-time closed loop system and get a richer condition, but the stock sensors will always toggle at the same point.

I could be wrong, and hope someone will straighten me out if I am, but this sounds logical to me.

Chief

[WVULTRA]

It was confusing for me! Here is what I learned and why I ended up using the SERT on my 07.
The ECM is only using the O2 sensor feedback signal when the system is in closed loop mode. Closed loop mode occurs only under certain conditions which are light load, steady speed part throttle, constant mode(where most of us spend majority of time on the highway). It is only after these conditions that the  EFI will go into closed loop mode and the ECM will adjust until the O2 crossover point is in the 14.7:1 A/F range. The beauty of the race tuner is that you can adjust the bias (map) to have the closed loop AFR be say 14.2:1 using the feedback from the narrowband sensors (hence the +/-0.5 afr adjustment). Otherwise you are using the programmed map in the ecm or with the PC3, the piggyback adjustments to the base map.

kojak:

After using the sert for some minor tuning on the '05RK, and reading everything I could on the latest version I tend to agree with your analogy though Chief also makes good points.

From the "H" software:

Tuning with Closed-Loop

Only calibrations that are closed-loop capable can be used for closed-loop operation. When a calibration is opened in Tuning Mode, a box in the upper right region of the screen will indicate if a calibration is intended for open or closed-loop operation.

The AFR table controls the operating conditions in which the ECM will enable closed-loop. The AFR cell must equal 14.6 for the ECM to enable closed-loop operation. This allows the user to control if and when the bike is in closed-loop using the AFR table.

For tuning of the VE tables, the recommended method has not changed. The AFR table should be set to 13.5 in all cells; this will put the bike into open-loop operation. The VE tables are then tuned to achieve the 13.5 in all conditions. Upon completion, the AFR table should be returned to its previous settings. This will return the bike to closed-loop operation.

The new table that has been added this year is the Closed-Loop Bias table. This table is used to shift the AFR richer or leaner during closed-loop operation. This table is a function of engine speed and map load. The cell values are the switching voltage that the ECM controls to. A lower voltage will control leaner, and a higher number controls richer. This table is used by the ECM in addition to the AFR table to determine what AFR to control to.

Example: Using calibration 141NX001. Looking at 1750 rpm and 40 kPa, the AFR table shows 14.6 and the Closed-Loop Bias table shows 447mV.  With these values, the ECM will be in closed-loop operation and will control to approximately 14.4. In order to change the fuel delivered to the engine in this condition, the Closed-Loop Bias table would be used. 500 mV will make the mixture slightly richer, and 400 mV will make the mixture slightly leaner.

It has been noted on several sites that maxing out the CLB Table will lower the Closed Loop operation to a requested 14.2:1 if the bike has been tuned and the VE Tables are correct.

If you open one the SERT Touring Tuning files, and max out the AFR table values, there are a surprisingly large number of cells that will accept the 14.6 value that triggers Closed Loop.

Playing with the SERT coupled to the '07 Ultra for an hot idle Data Recording helped me to understand why there's so much heat being generated.  The ECM is operating in Closed Loop even at idle!

 

[kojak]

Chief, what you are saying is essentially correct. In closed loop, the 02 sensors are sending feedback to the ecm as lean or rich and the ecm bounces around the target trying to achieve the 14.6:1 ratio. In WOT and Decel, the system is in open loop and the sensors are not working. WVULTRA is also giving the right type of info. You can set the VE tables to have the bike run at 14:2:1 in closed loop with the o2 sensors engaging the ecm trying to achieve the 14.6:1 ratio as the ideal stoichometric ratio.
To Hoist's point, is this better than the PC3 with O2 eliminators? Depends on what kind of riding you do, imho. Bikes tuned properly with either should run fine. I like the idea of running in closed loop on my 1000 mile touring trips. Its probably a smaller benefit than I'm making it out to be but still a benefit. Look for the next generation of power commanders to use some form of a o2 sensor system.

[Twolanerider]

My spin is heading.  Glad I got the autotuning Thundermax.  No more  or or even .  So far just  and .

[Chief]

Chief, what you are saying is essentially correct. In closed loop, the 02 sensors are sending feedback to the ecm as lean or rich and the ecm bounces around the target trying to achieve the 14.6:1 ratio. In WOT and Decel, the system is in open loop and the sensors are not working. WVULTRA is also giving the right type of info. You can set the VE tables to have the bike run at 14:2:1 in closed loop with the o2 sensors engaging the ecm trying to achieve the 14.6:1 ratio as the ideal stoichometric ratio.
To Hoist's point, is this better than the PC3 with O2 eliminators? Depends on what kind of riding you do, imho. Bikes tuned properly with either should run fine. I like the idea of running in closed loop on my 1000 mile touring trips. Its probably a smaller benefit than I'm making it out to be but still a benefit. Look for the next generation of power commanders to use some form of a o2 sensor system.

OK, the mud is clearing. So the narrow band sensors are not just open or closed, but do have a variable voltage, but only over a narrower range of AFR readings. This invalidates my idea of how it all worked. I thought it was yes or no. Sounds like there is a maybe in there too.

So I stand corrected.

Thanks guys.

Chief