GMC Repair: 2001 Yukon idle problems, crankshaft position sensor, gmc yukon

Question
A short while ago I asked a question about my Yukon idle problem and an expert in gmc repair recommended that I have my crankshaft position sensor changed or it could be alternator problems.  I went to the GM dealership and bought a new crankshaft position sensor and had it replaced today.  The problem still exists.  When I come to a sudden stop my truck idles below 500 rpms and sometimes dies.  All help is appreciated.  Thank you.  2001 gmc yukon.

Answer
Hello courteny
this is time for a diagnostiac test .
todays cars and trucks can not be guessed at
it is a differnt world.

so that expert was wroang .

Good luck to u hun and if you need more help just let me know and u have a pretty name pete