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Confused about AutoTap numbers

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Old Apr 17, 2002 | 02:47 PM
  #1  
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Default Confused about AutoTap numbers

Recently got the car back from Agostino's. Installed cam 222/222/.544/.544/114, Grots/cats, LS6 intake, and ported throttle body. After about 100 miles the SES light came on, code PO135 B1O2 sensor1. Cleared the code and the light hasn't come on again.

Just did an AutoTap run and got the following:

There are 345 frames which include a couple WOT bursts in 2nd gear.
Average timing was 36.83 with only one frame showing KR at 0.5.
Average B1LTFT while in fuel cells 1-19 = .426
Average B2LTFT while in fuel cells 1-19 = .370
Average B1O2 sensor1 in fuel cell 22(WOT) = -.040
Average B2O2 sensor1 in fuel cell 22(WOT) = +.206

Any help in analyzing this is appreciated.
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Old Apr 18, 2002 | 09:37 AM
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Default Re: Confused about AutoTap numbers

When you average out your timing advance, B1S1 & B2S1 O2s, make sure your at WOT or at least the WOT fuel cell. Those readings look like either the after-cat O2s or not at WOT, and the timing number looks more like a normal cruising #. Otherwise, I'm not sure what is happening there.
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Old Apr 18, 2002 | 10:44 AM
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From: Clarkston
Default Re: Confused about AutoTap numbers

Neg O2 number huh? Never seen that before. Take your B1 cruise readings and chart them out. You should get a nice ocilsating pattern (line a sine wave) - in fact chart out both your O2's and compare them. (You could chart them in Atap but with so many frames it may be a little compressed)

Mark
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Old Apr 18, 2002 | 11:10 AM
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Default Re: Confused about AutoTap numbers

Your ATAP numbers make no sense. You are not reporting what you think you are.

O2 numbers should never be negative. It should always between 0.00mV and 1.00mV. If it is really negative, maybe that is why you got an error code.

And what are those lterm fuel trims values????
What is .426?? do you mean 0.426% or 42.6%???

I take two kinds of log files with ATAP, cruising around and WOT. While cruising around, I am mainly interested in the lterm fuel trim values B1 and B2. I also record the engine rpm, MAF flow rate, and maybe fuel cell number. I want my Lterm fuel trims to be between -5.00% and 0.0%. I adjust the MAF table with LS1Edit to achieve this.

For WOT log files, I record Lterm B1, RPM, MAF flow rate, KR, TPS, timing, and O2 sensor B1. I try to get the O2s around 880mV to 890mV while at WOT (TPS=100).
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Old Apr 18, 2002 | 06:34 PM
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gwj
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Default Re: Confused about AutoTap numbers

Wow, I missed that negative O2. Never seen that before. Anyway, for the O2s, make sure your logging B1S1 and B2S1.
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Old Apr 18, 2002 | 09:04 PM
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Default Re: Confused about AutoTap numbers

Damn. It's not the car. It's my spreadsheet ignorance showing. Wrong averaging formula and I just didn't see how this could be possible.
Dumbass. <img border="0" title="" alt="[Embarrassed]" src="gr_emb.gif" /> Thank you guys for trying to help.

<small>[ April 18, 2002, 09:15 PM: Message edited by: Silver99Z ]</small>
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Old Apr 20, 2002 | 01:09 PM
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Default Re: Confused about AutoTap numbers

Okay. I put on my dunce cap and figured out the spreadsheet. Correct numbers are:
B1LTFT = -0.339
B2LTFT = -1.983
B1O2 = .936
B2O2 = .939
I'll get a MAFT and lean it out. Thanks again to you guys who tried to help this dummy.
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