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Car not following commanded AFR?

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Old Apr 20, 2006 | 05:18 AM
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Default Car not following commanded AFR?

I was watching HPtuners while my car was warming up idling in the garage and I noticed that the car was not following the commanded AFR. It was commanding like 13.X when I noticed it and the WB was showing around 16.X. Once it warmed up and the commanding went to 14.63(assuming went into closed loop) the WB jumped down to around 14.4-15.0 range. Any ideas?
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Old Apr 20, 2006 | 07:36 AM
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99whitews6, meet the Open Loop Fuel Adder table. It works just like PE, only it is referenced when your car is in Open Loop (O2's are only used in closed loop). To see it, go to Engine->Fueling->Open & Closed Loop->OLFA. I think its in the top left on HPT.

The wideband values being funky are probably just the sensor getting warmed up. The LM1 I use does something similar a lot of the time.
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Old Jan 12, 2008 | 07:49 PM
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do we need to alter that table any?
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Old Jan 13, 2008 | 01:32 AM
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AIR pump running, would mess up any wideband reading.
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Old Jan 13, 2008 | 11:40 AM
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Originally Posted by jimmyblue
AIR pump running, would mess up any wideband reading.
I second this suggestion.
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Old Jan 15, 2008 | 09:05 PM
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I know it is a pretty old thread but new info is good info.
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Old Jan 19, 2008 | 09:54 AM
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I'm having this problem too.

Wideband correctly tracks stoich and PE within a couple of %, when the car is fully warmed up.

But it shows lean during warmup. Even at 150 degrees ECT, it's still running leaner than stoich, even though the commanded afr is still rich. Finally around 176 it's almost there but still lean, and at 190 it's running just a tad richer than commanded.

When it's showing lean, it runs like it's lean too, hesitant to get moving. So it's not a "false" wideband reading.

60 lb mototrons, SD tune.

For reference, my afr error histogram shows my VE is right on at idle at 190 degrees.

The same histogram wants me to add 15% to VE at coolant temps under 170.
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Old Jan 19, 2008 | 08:10 PM
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what is "PE" ????
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Old Jan 19, 2008 | 08:20 PM
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Power Enrichment. Comes on at a particular throttle opening. (depending on the tune)

I'm running 14.7 stoich, 13.0 AFR for normal PE, and 11.5 AFR for PE under boost.
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