O2's and speed density
05-25-2005, 11:57 PM
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O2's and speed density I thought I would fool around with SD today and I was surprised it ran rather well the first time unplugging the MAF. I drove it a while like that and did some logging and ran it all through VE Master for adjustments but while I was logging, I noticed my right O2 voltage was extremely low. I thought it was crapping out on me. But after the temp dropped from 70 to 53 tonight, SD wasn't such a good idea and the car ran like **** so I changed everything back to MAF mode. And like magic, my right O2 is working again. Anyone know anything about why this happened?
05-26-2005, 12:34 AM
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Here is what I think is going on. No O2 switching means no closed loop fuel control. O2 switching means closed loop is working. With no MAF sensor, your right oxygen sensor remained low because your air fuel ratio was above stoichiometric (lean) and your VE table isn't good enough for closed loop control to lock in. When you reconnected the MAF sensor, closed loop control resumed working.
Last edited by Gary Z; 05-26-2005 at 08:59 AM.
05-26-2005, 11:06 AM
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Ok that makes a little sense to me. What about the left? I wonder why it didn't do the same? Could I continue to log and edit through VE Master and get over that?
05-26-2005, 01:02 PM
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The two sides are never exactly equal. Narrowband oxygen sensors are very sensitive to small changes. The right side was probably close to working.
Last edited by Gary Z; 05-26-2005 at 01:20 PM.
05-26-2005, 01:37 PM
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I just noticed you have an ODB1 LT1 unplugging the maf sends the car into open loop IIRC. My statement above talks about the LS1 and OBD2. Which way did the o2 flatline lena or rich?
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05-26-2005, 03:12 PM
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Well I changed the file to speed density so I am assuming it eliminates any "modes" when something goes down. During all the SD stuff, my BLMs on the right, low voltage O2 were over 128 so I am assuming that means lean.
