Ok guys I have a 1995 Tahoe. Their is a cable on the throttle body next to the actual throttle cable, and wondering what is its purpose. Maybe something to do with the transmission shift points? If not how can I adjust the transmission's shift points?

Thanks

 

That is the Throttle Valve (TV) cable, do not mess with it if your transmission is shifting properly.
If this cable is not adjusted correctly your transmission will be damaged.

The shift points on your 1995 Tahoe are controlled electronically by the ECM, you can replace the E-PROM with a performance chip or you can install a very inexpensive item made by B&M called a transmission shift improver kit.