Transmission is downshifting when it shouldn't

[Ryushin]

I have a new problem with my '92. If I'm cruising on a level grade at a constant speed in 4th gear, though sometimes it will do it in 3rd as well, it will downshift from 4th to 3rd or 3rd to 2nd for a few seconds and then upshift back to the gear it should be in. Is this a brake band adjustment that is needed? Reading the brake band adjustment threads, this didn't seem to be what was occurring for people. I'm at a loss right know about what could be causing it.

[processengr]

Both of our '92s did this, along with a delayed shift from 1st to 2nd when cruising with light throttle on level ground. Both had codes for bad throttle position sensor. Cleaned and recalibrated both...ended up replacing both (about $200.00 each from 1st Subaruparts). Solved the problem in both cars, improved gas milage too.
Good instructions are on this website's "How to" section to test and clean/recalibrate the "TPS" as well as how to pull trouble codes.

[TomsSVX]

yeah, my teal was doing that when I had issues adjusting the tps in it... Gotta be sure it is precise or else it will tell the ecu the wrong thing while driving and mess the TCU up at the same time. Try adjusting the TPS back to .48-.50 volts and see what happens

Tom

[Ryushin]

So what are the odds that it's defective and I should just replace the TPS. I guess I can just hook up the ohm meter to it and see where its at right now. Thanks for the tips. At least it's not the tranni going bad.

[Hocrest]

Start off by adjusting it. If you can't get it adjusted properly, then look for a new one.