https://www.the12volt.com/ you can look up wiring for almost any vehicle to install remote starts radios lists the colors for wiring in factory harness and what they are for
http://www.rockauto.com/en/moreinfo.php?pk=1352622&cc=1353721&jsn=431 here it is on rock auto and the next link is the price http://www.rockauto.com/en/catalog/chevrolet,1999,tahoe,5.7l+v8,1353721,emission,vapor+canister+vent+valve+/+solenoid,16992
your best bet is to replace it. its probably the original one from new I went thru cleaning the one on our 5.3 Denali Envoy code cleared passed inspection for a sticker and code was back a short time later replaced it no light going on a year and a half now
honestly pay pal is the way to go cause it protects the buyer,and there has been an issue on here with a member that was selling the same stuff and another member got stiffed out of a few hundred dollars would hate to see something like that flair up again on here.Also make note i'm not saying...