[David Cohen]

Twisting the TPS eliminated the worrisome downshifting behavior and let the torque converter lock up properly. Hurrah! Unfortunately, the computer finally noticed the wonky throttle position readings and lit up the check engine light. Passengers seem to like letting me know that my CEL is on. Sigh.

I ended up replacing the TPS with one I bought from another SVX World Network member (thank you, Galen!), and that definitively solved my problems. My SVX is driving and shifting perfectly now.

Thanks to everyone who offered help!

—David