(tps) Throttle Position Sensor & Problems Downshifting

[MikeDubb]

Can a faulty TPS cause my '90 LS400 to keep from downshifting at full throttle? I'm getting an error code 41 which is telling me that the Throttle Positon Sensor is faulty but I'm idling just fine.

The funny thing is, is that it is not a constant problem. At random times, the TRAC light comes on and when it does, the car doesn't downshift. I'm also getting poor gas mileage (15-17mpg) and I drive 25mile each way on the freeway to work each day. I've read in other posts that a dirty mass airflow sensor (MAF) will sometimes cause this problem as well.

Any thoughts?

[mehullica]

Bad TPS can cause all kinds of driveablity problems.