My AFR shoots to 29:1 when im off the gas for a few seconds.
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2015 W204 c63 507
My AFR shoots to 29:1 when im off the gas for a few seconds.
so I have a theory that even though I've done everything under the sun to fix my High LTFT It still fluctuates way too much. I changed one out of my 2 o2 sensors that may have been giving me issues but now my readings are all over the place. I have noticed that every time I decelerate by letting go of the gas my AFR shoots to 29.7:1 I might be fudging up the actual ration but it is 30-29.1 causing an extreme lean condition and my STFT to freak. Is this a tune issue?
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2012 P31 C63 Coupe Trackrat, 2019 GLE63S Coupe Beast
so I have a theory that even though I've done everything under the sun to fix my High LTFT It still fluctuates way too much. I changed one out of my 2 o2 sensors that may have been giving me issues but now my readings are all over the place. I have noticed that every time I decelerate by letting go of the gas my AFR shoots to 29.7:1 I might be fudging up the actual ration but it is 30-29.1 causing an extreme lean condition and my STFT to freak. Is this a tune issue?
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Joined: Sep 2016
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From: NY
2010 C63 2019 GLA45
This is normal. Also log open loop-closed loop status you'll find that change in decel.
As far as o2 issues, don't look at values, look at graphs.
When you change one of the two sensors in the same row, it will be faster to respond than the other. As time goes by, the new one will start to fall inline with the old one.
I had this problem with my rears. I changed both, but found a good deal with one on ebay.
The novelty for me is that the person that was selling this sensor on ebay, apparently went through the trouble of replacing their sensor, re-using the new sensor box, detailing the old sensor, to where it was spotless, putting antiseize on the threads, re-using the shipping protective plastic cap.
Now, in the past, it was easy to catch such sneaky vendors, because every plastic piece used to have a wheel cast on it, with a date. So you see that this was an old piece. But this in time caused trouble for vendors, so now manufacturers encrypt the date into some form of code, where you can't tell the date in many cases.
Anyway, so upon viewing the graph on xentry (stupid thing will show you all the parameters real time, but no logging, unless there's some sort of secret command), I could see on of the rears being more lazy and then just running a parallel AFR line with the other. I narrowed it down to the right side one and replaced it .... again.
Now this new one is faster to respond than the 6 months older one, but every day that goes by, they become closer.
As far as o2 issues, don't look at values, look at graphs.
When you change one of the two sensors in the same row, it will be faster to respond than the other. As time goes by, the new one will start to fall inline with the old one.
I had this problem with my rears. I changed both, but found a good deal with one on ebay.
The novelty for me is that the person that was selling this sensor on ebay, apparently went through the trouble of replacing their sensor, re-using the new sensor box, detailing the old sensor, to where it was spotless, putting antiseize on the threads, re-using the shipping protective plastic cap.
Now, in the past, it was easy to catch such sneaky vendors, because every plastic piece used to have a wheel cast on it, with a date. So you see that this was an old piece. But this in time caused trouble for vendors, so now manufacturers encrypt the date into some form of code, where you can't tell the date in many cases.
Anyway, so upon viewing the graph on xentry (stupid thing will show you all the parameters real time, but no logging, unless there's some sort of secret command), I could see on of the rears being more lazy and then just running a parallel AFR line with the other. I narrowed it down to the right side one and replaced it .... again.
Now this new one is faster to respond than the 6 months older one, but every day that goes by, they become closer.
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Joined: Aug 2009
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C63 AMG
As far as o2 issues, don't look at values, look at graphs.
When you change one of the two sensors in the same row, it will be faster to respond than the other. As time goes by, the new one will start to fall inline with the old one.
I had this problem with my rears. I changed both, but found a good deal with one on ebay. The novelty for me is that the person that was selling this sensor on ebay, apparently went through the trouble of replacing their sensor, re-using the new sensor box, detailing the old sensor, to where it was spotless, putting antiseize on the threads, re-using the shipping protective plastic cap.
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Joined: Feb 2011
Posts: 1,752
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From: London, UK
W212 - E63 AMG
so I have a theory that even though I've done everything under the sun to fix my High LTFT It still fluctuates way too much. I changed one out of my 2 o2 sensors that may have been giving me issues but now my readings are all over the place. I have noticed that every time I decelerate by letting go of the gas my AFR shoots to 29.7:1 I might be fudging up the actual ration but it is 30-29.1 causing an extreme lean condition and my STFT to freak. Is this a tune issue?
