I hooked up the wideband O2 sensor and took the car out to do some logging. I wanted to make sure that the changes I did with PE didn't throw the AFR off, making it too rich when PE kicked in.

Actually didn't seem to change a thing as far as AFR is concerned. There are some lean and rich spikes here and there, particularly going through the gears from a dead stop, but nothing really drastic. Cruising the stock O2 sensors are only fluctuating around 5 percent or less, so that's not bad at all.

I may sharpen the slope for PE just a tad more in the 1500 to 2800 rpm range. I think that could use just a little bit more improvement. I just have to be careful I don't over do it. The PE table doesn't seem to care that 1800 rpm in second gear at 30 percent throttle doesn't have the same demands as 1800 rpm in sixth gear at 30 percent throttle. Haven't seen any bogging down yet, but I don't want to push this too far.

One thing I did notice since I was paying a lot of attention to throttle pressure while I was data logging. The throttle pedal is not linear as far as the PCM is concerned. Just barely touching the gas pedal puts it at around 7%. From 7% to 25% is just slightly more pressure. But it seems to widen out quite a bit at the top end when you get closer to 100% WOT. So you get a lot of throttle movement in relation to pedal pressure at the beginning, but it gets much softer up at the top.

Must be that seat of the pants acceleration gm put into it. Wonder what table you can use to scale it down?

I recall that there are one or more tables related to throttle plate movement that you have to be careful messing with because if the parameters go too far out of range from what the TAC module is expecting to see, you can brick your PCM. But I don't recall seeing anything that handles scaling of the voltage from the gas pedal sensor itself. As I have mentioned before, there apparently are lots of other tables the PCM references that the available programs we have for tuning apparently do not address. I also recall seeing someone selling a mod for the gas pedal that apparently changes the voltage slope from the gas pedal sensor which would probably do the same thing. Especially if it were programmable enough that you could select what you preferred.

I still need to play around with PE some more as I was specifically playing around with the gas pedal in all sorts of RPM ranges to see what affect the changes I made were having on AFR. And I noted that there were instances of gas pedal position and RPM being such that PE SHOULD have kicked in, but did not. So there is likely another table or two controlling PE that I need to review. The smart thing would be to have PE also triggered by load, which could be determined by the MAP sensor. That would likely take care of the problem I mentioned earlier about the differences in engine loading based on what gear you are in.