Transmission down shift
 

I have a 1997 GMC Sierra 4l60E 5.7 1500 The transmission works fine, but when put the gas to the floor to down shift it only revs up. It does not shift down. Anybody know what could be wrong.:confused:

Test your TPS(Throttle Position Sensor). These wear out and can cause shifting problems.

Thanks for the reply. Now can you tell me where it is at, And how do I test it. :)

Thank You I will check it out. I was doing a search in here and seen that a check engine lite and the O2 censer could cause the same thing. And I had that. So I will drive it and see. Thanks again. :)

Oh yeah now that I remember I had the same thing result from a bad O2 sensor.