No codes beyong P0171, which only comes up when the car sit'* idling for more than 1 minute. Code and CE light go off after a little driving.
But to answer your queston, no CE light or codes from the tranny.

Marty, was your torque converter replaced? Velocity of the TC is a big factor with age.
What are your trans temps when this happens?

Do you have more than 10 rpm'* of slip in TCC lockup?

There is no way your PCM will alow a shift that late unless there is a problem involving the torque converter. The PCM loses track of slip rpm'* at 255.

The torque converter or it'* controls are failing, or your PCM is trying to protect you for some other reason at the higher shifts (performance mode).

This wasn't a full rebuild if I recall.

The torque convertor was replaced with a new unit (according to rebuild reciept).

When I had it scanned last time I wasn't along for the ride, but when I asked they said the tranny temp was right where it should be.
I had seen 230* when I scanned at Gordy'* but later realized that I had cardboard between the radiator and tranny cooler preventing the tranny cooler from cooling anywhere near it'* full capabilities. Tranny shop pulled the cardboard out when they fixed the line that had popped off and said they saw tranny temps max out around 150-160'ish (exact * was posted here somewhere).

TCC slippage is a # I'm not recalling.

I think I'm going to drop the car off at the shop tomorrow before I head out to NE for a week -should be enough time to address the problem if it'* theirs.

Rebuild fairly extensive. Only thing I wonder about is the valve body, which shows as being replaced on the reciept, but on a test drive 2 months ago to figure out my mis-shifts (2-1, 3-2-1) the tech who rode with/test drove also, said he thought they had just flushed my original and re-used it, and if there was scratches from the metal shrapnel that passed through that could've been the cause for the mis-downshifts.

Definately seems like slip. Shift points are based on MPH not RPM, so if the trans or convertor is slipping that would cause it to hit the limiter before shifting.

Honestly I would suspect convertor before trans.

Shawn