not too long ago i did a motor rebuild...and of course i had to unhook everything. When i put the tranny back and took it for a test drive, i saw the speedometer is reading 15mpg less than it should...i know this cause i had my friend drive next to me and yell out the window. is it the speed sensor? i tried pulling it out and checking it out...saw nothing wrong with it. Thanks in advance

 

Have any other friends or any other VSSs laying around? Its not hard to pull out and plug a different one to try it out to see if that could be the problem.