Checked 2002 Z06 Fuel Trim Cells

[rbartick]

Car not moving:
Open Loop Idle : 20
Closed Loop Idle, No A/C : 19
Closed Loop Idle, A/C : 18


Deceleration : 21
WOT : 22

Cells 0 - 17 are used while driving. They are also used when revving in neutral. The cell used is based on engine load. Low loads get the lower cells, higher loads get the higher cells. You normally get Cells 0 & 1 when the car is moving and the engine is idling. This can include neutral or in gear.

[LS6DAVE]

At WOT, if you had a +LTFT, what cell would be used to determine how much extra fuel to add to your open loop power enrichment???? 22?

[rbartick]

The best way to tune WOT A/F ratios is with a wideband O2. I do not think that you can use a LTFT value as a guide. In addition, the stock O2 sensor readings are not worth all that much at WOT. Don't spend much time analyzing their readings at WOT, they are not designed for WOT operation.

If you are really daring I guess you could lean out the PE a few % at a time and then check for knock at WOT&High RPM. If you get knock back off the throttle immediately and go a little richer. This would be dangerous, but it could get you fairly close. I would not take more than a few % of the PE without a wideband reading.

You should also monitor your IAT. If the IAT goes above 90F you start to lose timing, which could enrichen the A/F ratio.