Closed Loop Operation Calculation Issues with Fuel Trims

FlashPro questions & answers specific to the 2006-2009 (US, UK, Asia) S2000
xxshift
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Re: Closed Loop Operation Calculation Issues with Fuel Trims

Post by xxshift »

Significant improvement (as seen in the attached picture and datalog) by simply enabling the secondary O2 sensor while keeping it unplugged.

It still goes pretty lean (~16.5AFR) for the first ~10 seconds after startup before the closed loop system kicks in, so if you have any advice on how I could richen the mixture for only those 10 seconds without affecting the base map or closed loop trims, that would be amazing. I feel like I'm getting a lot closer now.

Let me know if you come up with a different way of disabling the secondary O2 (as you mentioned in your last post) since I'm now running with a CEL.
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Hondata
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Re: Closed Loop Operation Calculation Issues with Fuel Trims

Post by Hondata »

What happens if the SO2 is disabled and plugged in?
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xxshift
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Re: Closed Loop Operation Calculation Issues with Fuel Trims

Post by xxshift »

Hondata wrote: Fri Feb 19, 2021 12:47 pm What happens if the SO2 is disabled and plugged in?
I would have to go find the sensor (probably buried somewhere) and plug it in.

So I've retuned the low fuel map from scratch and the lines on the map are significantly smoother flowing now. I've managed to run around 0% LTFT and -2 to 2% STFT all day long so I believe this issue is resolved. I wish there was a way to have my cake and eat it too, by getting rid of the check engine light since the secondary O2 is no longer disabled in Flashpro.
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Hondata
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Re: Closed Loop Operation Calculation Issues with Fuel Trims

Post by Hondata »

The problem is that the Honda ECU always looks for the SO2, even when unplugged or disabled. I can look to see if there is an alternate way to stop the ECU using the SO2, but it might take a little while. The error condition is what stops the ECU using the SO2, not what I originally thought but useful to know in order to fix the problem.

If you want to test some software releases to disable this then let us know (your forum email does not work).
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xxshift
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Re: Closed Loop Operation Calculation Issues with Fuel Trims

Post by xxshift »

Hondata wrote: Sat Feb 20, 2021 8:54 am The problem is that the Honda ECU always looks for the SO2, even when unplugged or disabled. I can look to see if there is an alternate way to stop the ECU using the SO2, but it might take a little while. The error condition is what stops the ECU using the SO2, not what I originally thought but useful to know in order to fix the problem.

If you want to test some software releases to disable this then let us know (your forum email does not work).
I'd be happy to test. I build and test software everyday so I'm sure we can get through it pretty quickly. My email address is my username @ gmail.com
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Hondata
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Re: Closed Loop Operation Calculation Issues with Fuel Trims

Post by Hondata »

Email sent. Let me know if no email arrives as gmail might filter the attachment.
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nivlac978
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Re: Closed Loop Operation Calculation Issues with Fuel Trims

Post by nivlac978 »

Any update to this? I just installed a turbo and removed my SO2 and disabled it to find this weird issue happening as well. I originally had my SO2 in my test pipe plugged in and enabled for emissions. There are 2 options for the SO2 "secondary oxygen sensor enabled" and "secondary oxygen sensor header enabled." I had both disabled but I don't know what the second option means. I thought it was a typo and should say heater but I'm not sure. I don't want to have to add a third bung into my downpipe for the SO2 to not have a light on.
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Re: Closed Loop Operation Calculation Issues with Fuel Trims

Post by Hondata »

We never heard back from the original poster.
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s2000cr
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Re: Closed Loop Operation Calculation Issues with Fuel Trims

Post by s2000cr »

Hi,

I have the same issue with fuel trims. I can work with Hondata to get this resolved. Please send me an email. This will help the S2000 community.

Thanks.
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Re: Closed Loop Operation Calculation Issues with Fuel Trims

Post by Hondata »

Start you own thread with full information. I'll close this one.
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