Fuel trims not logging in Evoscan - only getting 0.1?
Nov 25, 2010, 08:37 PM
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Fuel trims not logging in Evoscan - only getting 0.1?
LTFT low, LTFT mid and LTFT High are all giving me values of 0.1 and nothing changes during cruise, wot and idle?
Any help with diagnosing the issue would be helpful, I would really like to see what is going here.
I do get valid values for everything else, STFT works fine but no other fuel trims change at all during logs.
TIA
Any help with diagnosing the issue would be helpful, I would really like to see what is going here.
I do get valid values for everything else, STFT works fine but no other fuel trims change at all during logs.
TIA
Nov 26, 2010, 08:08 AM
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make sure that your rear O2 sensor is enabled. I know that on the 8's you need to have the rear O2 sensor enabled in order to properly log fuel trims.
If you start getting the p0142, then you know the rear O2 is enabled, then you should be able to start logging trims.
Also try logging the O2 sensor voltages. Make sure that you are getting some readings. If not, then you may have a dying front O2 sensor.
Josh, if you want some help contact me offline and we can work out a trade.
fender rolling for some diagnostics and fuel trim tuning??
If you start getting the p0142, then you know the rear O2 is enabled, then you should be able to start logging trims.
Also try logging the O2 sensor voltages. Make sure that you are getting some readings. If not, then you may have a dying front O2 sensor.
Josh, if you want some help contact me offline and we can work out a trade.
fender rolling for some diagnostics and fuel trim tuning??
Nov 26, 2010, 10:19 AM
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I think I should be able to work this out, thanks for the offer chris. Fender rolling can be arranged, but it cost $... I'll give you the autox'ers discount 
The cause might be because I have disabled the rear o2 sensor then?
The cause might be because I have disabled the rear o2 sensor then?
Nov 27, 2010, 08:37 AM
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I know on my 8 that the disabled rear O2 can cause this.
Also keep track of how long it takes the front O2 sensor to respond on the first cold start of the day. If it takes longer than your wideband, then chances are the front O2 sensor is dying.
Also, a failing front O2 sensor will also cause the fuel trims to wander which ultimately causes lean and/or rich conditions at the wrong time.
Also keep track of how long it takes the front O2 sensor to respond on the first cold start of the day. If it takes longer than your wideband, then chances are the front O2 sensor is dying.
Also, a failing front O2 sensor will also cause the fuel trims to wander which ultimately causes lean and/or rich conditions at the wrong time.
Nov 27, 2010, 02:21 PM
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I know on my 8 that the disabled rear O2 can cause this.
Also keep track of how long it takes the front O2 sensor to respond on the first cold start of the day. If it takes longer than your wideband, then chances are the front O2 sensor is dying.
Also, a failing front O2 sensor will also cause the fuel trims to wander which ultimately causes lean and/or rich conditions at the wrong time.
Also keep track of how long it takes the front O2 sensor to respond on the first cold start of the day. If it takes longer than your wideband, then chances are the front O2 sensor is dying.
Also, a failing front O2 sensor will also cause the fuel trims to wander which ultimately causes lean and/or rich conditions at the wrong time.
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Nov 28, 2010, 02:15 AM
#9
I know on my 8 that the disabled rear O2 can cause this.
Also keep track of how long it takes the front O2 sensor to respond on the first cold start of the day. If it takes longer than your wideband, then chances are the front O2 sensor is dying.
Also, a failing front O2 sensor will also cause the fuel trims to wander which ultimately causes lean and/or rich conditions at the wrong time.
Also keep track of how long it takes the front O2 sensor to respond on the first cold start of the day. If it takes longer than your wideband, then chances are the front O2 sensor is dying.
Also, a failing front O2 sensor will also cause the fuel trims to wander which ultimately causes lean and/or rich conditions at the wrong time.
Nov 28, 2010, 05:52 PM
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and yes this is correct. However the funny thing is, the Trims come from the front o2. But if the rear o2 is disabled, nothing works. Rear o2 is a bull**** sensor for reading oxygen that passes the cat. basically just a sensor to keep track of how well the cat is doing its job, although some cars have other purposes for this sensor as well.
