[The Power of Dreams]

Very nice...........although I'm already afraid of the countless "Should I get Hondata or Cobb?" threads which shall ensue.

 

[The Power of Dreams]

I'm guessing it kills a warranty pretty much dead?

Seriously, how many times does the warranty issue have to be addressed?

If something malfunctions as a result of an aftermarket part, then Honda will not warranty the replacement part nor the labor to install the part. You would have to pay for it. It does not get any simpler than that.

 

[The Power of Dreams]

i know but i only understand about half of what is in that picture. i guess i will just have to take it slow and read the instructions and more about tuning

A basic knowledge of the fundamentals of engine mechanics and electronics is going to help you a lot. There's a lot to it. What amperage an air/ fuel sensor outputs as lean and rich to the ECM/ PCM. Some may say, "Don't you mean voltage?" For a basic heated oxygen sensor, indeed, but amperage is the more critical value for critical current and oxygen ion pumping air/ fuel sensors. Newer Hondas don't use heated oxygen sensors as the primary oxygen monitoring device anymore. They all have air/ fuel ratio sensors. Stuff like that is just the tip of the iceberg. How the MAF and MAP sensors work. Duty cycle for fuel injectors. Long term and short term fuel trim values. Don't even think of tampering with the ECM/ PCM until you are certain that know what you are doing unless you can afford a new engine. jm2c...take your time. In fact, let others be guinea pigs and learn from their mistakes. Trust me, there will be many (unfortunately). Don't come crying to dealerships about a warranty either because you fubar'd something. =)

 

[The Power of Dreams]

We started work on this in 2005. We announced publicly well over a year ago that we were going to make a product for the Si. How would it be to our advantage to delay a release? It would make no sense to do so. Sometimes the simplest explaination is the correct one.

That's all you really need to say. Anything more is just inviting people to have a pissing match with you because they're not satisfied with your explanation.

 

[The Power of Dreams]

I wonder if it has all the features that k-pro has. It is quite a bit less, I think k-pro was like 1100?

Hondatas website:

Because FlashPro is a different product from KPro, it has different features. Not all features implemented in KPro are possible with FlashPro.

 

[The Power of Dreams]

The Si sort of has a wideband O2 primary. It is fundamentally a narrowband but it has an oxygen cell pump inside it. It will pump oxygen into the exhaust strem. The ECU reads the amount of current it takes to get the AFR to stoich. Then in determines AFR from that. At least that's what my tuner told me.

Sort of.

There are two types of air/fuel ratio sensors used on Hondas and Acuras.

1. Critical current air/fuel ratio sensor
2. Oxygen ion-pumping air/fuel ratio sensor

Your description encompassed both, but the Si only has the former type.

One can distinguish between the two because the critical current air/fuel ratio sensor has four wires coming off the sensor and four wires on the harness end of the connector, while the oxygen ion-pumping air/fuel ratio sensor has five wires coming off the sensor and seven wires on the harness end of the connector. On the Si, the air/fuel ratio sensor has four wires coming off the sensor and four wires coming off the harness connector; therefore, the Si has a critical current air/fuel ratio sensor.

The critical current air/fuel ratio sensor does not pump oxygen. It has a zirconia electrolyte which is connected to a u-shaped heater element, in addition to a platinum exhaust electrode exposted to the exhaust gas and a platinum reference electrode exposed to atmospheric oxygen and contained within the reference chamber formed by the heater element and zirconia electrolyte. The oxygen concentration difference between the platinum electrodes (i.e., reference and exhaust) creates a potential difference (voltage).

The ECM/ PCM supplies 2.2v to the AFS+ wire of the AFR sensor, while it varies voltage to the AFS- wire of the AFR sensor depending on its commanded air/fuel ratio. At stoich, the AFS- voltage output to the AFR sensor would be 1.8v, causing a potential difference of 0.4v at stoich, compared to a voltage value of 0.45v at stoich for a heated oxygen sensor.

 

[The Power of Dreams]

Excellent summary. Now we just need to convince people that they can't use a voltmeter to diagnose problems with a current based sensor.

Actually, you can...in many ways, although using an ampmeter doesn't hurt.

 

[The Power of Dreams]

Cool man. Thanks for the lesson. I was close. lol..

Indeed.

I'd like to make a thread in the future about the critical current AFR sensor and how it works. Also, most people don't know that, in these types of systems (i.e. those which utilize an air/ fuel ratio sensor instead of a heated oxygen sensor as the primary), the ECM/ PCM also uses the secondary O2 sensor to modify the air/ fuel ratio. So, for those running without the secondary plugged into the bung, or for those using defoulers, the ECM/ PCM cannot modify the air/ fuel ratio optimally. It's not like back in the day with a basic primary heated oxygen sensor which was solely used for air/ fuel ratio modification. In that system, the secondary was used solely for determining catalytic converter efficiency. That's not the case anymore. Secondary has become an agent in air/ fuel ratio modification, so it's important for it to be placed in the exhaust stream, as it comes from the factory.

 

[The Power of Dreams]

Thx in advance if you dont mind to share your knowledge....

I always want to understand how the Honda 4 wires AFS work.

My first technical paper will be regarding the critical current air/fuel ratio sensor, although after Bill's encouragement, I'll be writing as many as I possibly can. Just stay tuned. I will do these in my spare time which is not much, but hopefully the first will be available on this site in a week. Nobody will be disappointed; they should find them insightful and informative, especially in light of Hondata's recent announcement. Photos, illustrations, electrical schematics and possibly HDS snapshots will be incorporated. People will want to know how components on their vehicle work so they can tune effectively.

 

[The Power of Dreams]

Doug, what type of programming exactly can the user perform on the FlashPro that would allow him to not utilize the secondary HO2S? Reason I ask is because the ECM/ PCM calculates the target air/ fuel ratio (AF FB CMD on the HDS data list) from the secondary HO2S input. The critical current air/ fuel ratio sensor is used for obtaining the actual air/ fuel ratio (AF Lambda on the HDS data list). The ECM/ PCM then adjusts the short-term fuel trim (represented by AF FB on HDS data list) to reach the target air/ fuel ratio.

 

[The Power of Dreams]

Doug, what type of programming exactly can the user perform on the FlashPro that would allow him to not utilize the secondary HO2S? Reason I ask is because the ECM/ PCM calculates the target air/ fuel ratio (AF FB CMD on the HDS data list) from the secondary HO2S input. The critical current air/ fuel ratio sensor is used for obtaining the actual air/ fuel ratio (AF Lambda on the HDS data list). The ECM/ PCM then adjusts the short-term fuel trim (represented by AF FB on HDS data list) to reach the target air/ fuel ratio.

Yes, the secondary o2 sensor can be disabled.

I want to know ---how--- considering my post above.

 

[The Power of Dreams]

I was pretty sure the Secondary O2 sensor was there to check the catalyst system efficiency. Considering the vehicle runs fine with or without a catalytic converter I don't see how disabling the sensor completely would make a huge difference other than I wouldn't be running around with a CEL. As far as a programming standpoint it may remove the reading from the equation and only use the pre-catalyst readings. Then again I know very little about the ECU in my car up until now because I haven't been able to tune.

In Hondas with a primary and secondary zirconia narrowband heated oxygen sensor, that is the case. The secondary is only used for monitoring catalytic converter efficiency.

But, newer Hondas use air/ fuel ratio sensors: critical current air/ fuel ratio sensors on vehicles without V6's, and oxygen ion-pumping air/ fuel ratio sensors on vehicles with V6's.

In these vehicles, the secondary heated oxygen sensor plays a significant role in air/ fuel ratio modification. It is what the ECM/ PCM uses to calculate a target air/ fuel ratio. Hence, my question.

 

[The Power of Dreams]

- How does disabling the secondary o2 affect air/fuel?
The target af will be set to defaults - there are many trim tables in play, but nominally stoichiometric in closed loop. It is not going to be very different from when the SO2 is being used. WOT will not be effected. If you're concerned I can do a datalog with the secondary o2 enabled and disabled.

Thank you for your response. I'll have to see more evidence --- not that I don't believe you. I just want to learn more about how the FlashPro works and impacts the ECM/ PCM. Thank you again for responding, Doug.