Lots O Questions mostly O2 related (w/ scan)
11-19-2007, 08:46 PM
#1
Lots O Questions mostly O2 related (w/ scan) As a preface the car is an 01 Formula with LS6 cam/heads, lid, and Dynatech LTs with cats. Car idles at 550rpm in gear when warm and 650 in park (stock idle speed table for A4). I had read guides on VE tuning with the narrowbands and decided to give it a shot in my free time. I ended up with a VE table that seems fairly close and so then I modified the MAF in order to bring the fuel trims in line during regular closed loop.
At the time I didn't think too much about O2 error with LTs, but as I was reading recently I have seen that many have had problems with the O2s "going to sleep" with long tubes and throwing off the fueling. I didn't manage to see any logs posted of how the O2s are supposed to oscillate at idle so I decided to go out and scan my car to see what it would do using a config that should have better resolution than the normal scanner PID I use that logs a bunch of crap. I left in speed, O2 mV for banks 1 and 2, and the STFTs just for the hell of it.
What do you think about the rate at which mine switch at idle and low throttle? The very end of the scan the car as been shifted into park and you can see the oscillations increase with the idle speed going up. Car has the OEM O2s as far as I know.
I also noticed a lot of threads about using Bosch 13111s or the equivalent Densos (rear Vette sensors) with longtubes and the possibility that they can stay warm longer. I saw many a post saying the 13111s had a higher wattage heater, but I also saw one where the difference was explained as a different shaped shroud as opposed to a change in the heater. At any rate I was just curious about whether or not anyone has used any other brand O2s as I have seen quite a few more for sale at various places. NTK were linked in one thread but I didn't see much about AC Delco / Delphi except as stock replacements, BWD, or Niehoff. Anyone ever used any of those sensors?
Thanks
At the time I didn't think too much about O2 error with LTs, but as I was reading recently I have seen that many have had problems with the O2s "going to sleep" with long tubes and throwing off the fueling. I didn't manage to see any logs posted of how the O2s are supposed to oscillate at idle so I decided to go out and scan my car to see what it would do using a config that should have better resolution than the normal scanner PID I use that logs a bunch of crap. I left in speed, O2 mV for banks 1 and 2, and the STFTs just for the hell of it.
What do you think about the rate at which mine switch at idle and low throttle? The very end of the scan the car as been shifted into park and you can see the oscillations increase with the idle speed going up. Car has the OEM O2s as far as I know.
I also noticed a lot of threads about using Bosch 13111s or the equivalent Densos (rear Vette sensors) with longtubes and the possibility that they can stay warm longer. I saw many a post saying the 13111s had a higher wattage heater, but I also saw one where the difference was explained as a different shaped shroud as opposed to a change in the heater. At any rate I was just curious about whether or not anyone has used any other brand O2s as I have seen quite a few more for sale at various places. NTK were linked in one thread but I didn't see much about AC Delco / Delphi except as stock replacements, BWD, or Niehoff. Anyone ever used any of those sensors?
Thanks
11-22-2007, 09:37 AM
#3
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Rule number one. ALL WAY GET WIDEBAND FOR TUNING. All other cases see rule 1. As for your question. What is the a/f. If the accual is same as commanded you have no problem.