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Thought I would give a quick update on my engine light issue in case anyone has the same problem. As in a previous post, my check engine light went stuck on after changing to a new exhaust and a Power Commander with Autotune but NO O2 optimizer connector. Tried a 3rd-party optimizer, and a home brew version with the resistor values recommended by Kaw’ee, and no matter what I tried (manual recommended clearing procedure AND my dealer clearing the code), the light remained on. Went thru the wiring and connectors one more time, and convinced myself the only item left to fail was the ECU itself. Found one on eBay for 69 bucks and installed today. SUCCESS! Was fairly shocked to see the light go off after I started the engine, and has remained off for 60 miles of several rides today.

All I can think of is in all my mods and subsequent troubleshooting, maybe I shorted something out and damaged that portion of the ECU...

JW
 

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So no 02 optimizer in now ?

Check your ECU # (pic)
Hate to say, But most the ones on eBay are the Recalled ones and throw away's and why there so cheep , But not sure if there ok or good enough with using a fuel controller .

(Stalling problem with original ECU's)
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Discussion Starter #3
So no 02 optimizer in now ?

Check your ECU # (pic)
Hate to say, But most the ones on eBay are the Recalled ones and throw away's and why there so cheep , But not sure if there ok or good enough with using a fuel controller .

(Stalling problem with original ECU's)
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All good points. The photos had all numbers visible so I looked them up first.

I was reluctant to pay full price for a new one from my dealer as THEY kept saying “it’s your wiring, not your ECU”. So in essence this was a proof-of-concept anyway. Since I don’t know the real history of where this unit came from, I’ll likely replace it over the winter with a new one.

And yes, I’m running a modified O2 optimizer with the resistor values you recommended. Thanks!

JW
 

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you by any chance have a wiring diagram resistor values and pinouts to build an o2 optimizer? I've been running my autotune with the O2 sensor plugged in as per Dynojet. I'd like to see if theres any change with a steady state o2 readout
 

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you by any chance have a wiring diagram resistor values and pinouts to build an o2 optimizer? I've been running my autotune with the O2 sensor plugged in as per Dynojet. I'd like to see if theres any change with a steady state o2 readout
There is a thread on here discussing this, not sure what the title was though. Pinout, connector, and suggested resistors was in there.
 

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Finally got the connectors in and they fit EXACTLY. Soldered up a set and it's currently in the Z125. I'll run it for a week or 2 to make sure there's not an intermittent fault before they show up on the site.

I did an experiment on my ZX10 with dual bungs and KNOWN, confirmed, and calibrated output on a real time display. Running the Z125 sensor on the second bung and measure the output voltage on the signal side while it's seeing 13.0. Then duplicate that voltage on the bypass plug so the bike thinks it's at 13.0 AFR. Simply bypassing the sensor in such a way that it doesn't trigger a CEL could cause poor running due to the ECM attempting to correct an imaginary condition, and not getting any feedback on it's corrections.

Anyways, the internal circuitry is going to have to remain a trade secret for now. :wink2: But barring unforeseen circumstances they'll be for sale beginning Friday Sept6.
 

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Kaw'ee, yours is in the mail because even though I didn't order from the sites you recommended they did help in tracking down the part number. :)

Constructive criticism is welcome.
 

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Is that just a shorting plug to trigger the internal blinky? They look nice, is that epoxy resin cast around the connector?

When I did my bluetooth to Buell adapter, I tried resin, but it made a huge mess. Ended up using hot glue and cutting it afterwords with a razor.
Thank you!

Not exactly a shorting plug. It duplicates the resistance of the heater circuit and steps the voltage down on the signal circuit to provide what the stock one does at 13:1 AFR.

It is a casting resin since I am sure hot glue won't last long, which would cause angry customers, and then I'll just be sad :(.
 

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Constructive criticism is welcome.
Still lots of confusion on when its needed and not needed on other sites.
And most wondering why power commander dis-continued it

[Quotes] / Yo this piece didn't come in my PCV box wtf! But in the instructions it doesn't even picture it or show anything about it? Do I need it? Do I jus leave the stock O2 sensor in it? What now...
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That is the 02 optimizer that comes with the AutoTune system. If youre only running the PCV witout Autotune this doesnt apply to you . If you decide to go the autotune route, youll be replacing your stock 02 with a wideband sensor (which requires a larger bung to be welded to your exhaust), then you would plug this optimizer into the stock 02 connector.
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This is no longer sold by Dynojet. I had to order mine through a company in Greece, and my CEL for the O2 sensor is still on.
Remembering most really know very little about it a Detailed but simple terms write up would be helpful for those thinking or knowing they need one..

When is it needed ......
With or without a fuel controller for better performance
With a fuel controller but no auto tune
With a fuel controller and with a auto tune
Or any other benefits.
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Whatever that green nightmare you staged it on is... that hurts my eyes.

=P

Looks good. +1 to Kaw'ee, the product description should describe who needs it.
That backdrop is what I like to call "seizure green". Found it at one of the fabric stores in the bargain bin! Go figure, lol.

According to Dynojet (direct correspondence with myself and dynojet for the record) they want a second bung welded in and have the Autotune Wideband run concurrently with the stock 02. I'm sure we can all imagine the reasons why that doesn't happen much. Why they stopped producing their "optimizer" is beyond me though.

It is a nasty can of worms trying to describe who needs it and who doesn't. I'm actually trying to avoid doing so.

Fact of the matter is I am in no position to tell anyone what to bypass and what not to. If you want to bypass an O2 then yeah I've got a part for that. Chances are if you need one you know what it is and what to do with it.

If you're not sure where to use this or don't know what it does then you probably don't need one.
 

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The reason Dynojet stopped producing a cheater is simple... The CARB hit them really hard! No more tunes that violate CARB levels of pollution. Same as what happened to Harley with the EPA. Pretty sure they saw the writing on the wall and changed all the tuner products to conform to EPA as well as CARB, lest they get fined again.

https://www.mcnews.com/community/topic/dynojet-fined-by-california-carb-for-powercommander/

That is an unconfirmed suggestion, but I bet it is pretty close to the truth. If you are required to keep an O2 in the system, and they can monitor it, then they can conform to all but wide open throttle levels (which are often not a tested throttle position).

Since the cheaters effectively fooled an ECU into doing "bad" things, it too was subject to fines and so was removed. I doubt anyone will ever confirm this openly.
 

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I don't understand how a PCV, Bazzaz or any piggy back tuner can work with the narrow band O2 sensor in place. When in closed loop mode, the ECU will target some AFR value (say 13.5 for arguments sake). The piggy back unit will then add/subtract fuel by X amount. The O2 sensor will read the AFR and the ECU will (attempt) to adjust to 13.5... It seems like when an actual O2 sensor is in place the two units fight each other. At least with a plug, the ECU will not think it will have to adjust the fuel table allowing the piggy back unit to do its job. I have been told this is not the case (by vendors), but nobody has been able to say WHY... other than it 'it works just fine for us'.
 

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I don't understand how a PCV, Bazzaz or any piggy back tuner can work with the narrow band O2 sensor in place. When in closed loop mode, the ECU will target some AFR value (say 13.5 for arguments sake). The piggy back unit will then add/subtract fuel by X amount. The O2 sensor will read the AFR and the ECU will (attempt) to adjust to 13.5... It seems like when an actual O2 sensor is in place the two units fight each other. At least with a plug, the ECU will not think it will have to adjust the fuel table allowing the piggy back unit to do its job. I have been told this is not the case (by vendors), but nobody has been able to say WHY... other than it 'it works just fine for us'.
^^ ABSOLUTELY. They just correct against each other until one (usually the stock system) exceeds it's adjustment threshold. This in itself can trigger a CEL.

When I run an autotune I bypass the stock 02. When I'm done with the map I'll lock it in and replace the stock O2 for minor day to day adjustments.
 

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Let's think about how a narrow band sensor works for a minute...

It is made to transition from making less than a volt, to more than a volt at 14.7 AFR. As mentioned, the computer is constantly trying to find the leanest condition possible, so it bumps it down and the voltage crosses to lower than a volt. Richen things up to get back to just where it crosses, and maybe over shoot, so go back to lean. On and on, back and forth because the only way for the ECM to know where things are is at the point of crossing. The narrow band sensors have no idea if you are at 14. 6 or 12.0. Just that it is rich and had a low voltage.
 

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Let's think about how a narrow band sensor works for a minute...

It is made to transition from making less than a volt, to more than a volt at 14.7 AFR. As mentioned, the computer is constantly trying to find the leanest condition possible, so it bumps it down and the voltage crosses to lower than a volt. Richen things up to get back to just where it crosses, and maybe over shoot, so go back to lean. On and on, back and forth because the only way for the ECM to know where things are is at the point of crossing. The narrow band sensors have no idea if you are at 14. 6 or 12.0. Just that it is rich and had a low voltage.
Exactly... Or at least I think we are saying the same thing...
 
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