egr valve, starting issues

my "service engine soon" light came on my 97 and the guy at auto zone hooked his little computer to it and said it was the egr valve. where is the egr valve and how hard is it replace. I seem to have misplaced my repair manual. also does aroud $110 sound about right for the price?

Also, today I drove the truck for about three hours. It had sat outside overnight in the cold and started fine in the morning. After the 3 hour drive it sat for about 1 1/2 hours and when I went to start it it turned over for about 5 times as long as normal. The truck has this problem often when it is cold. any advice on either issue is appreciated.

Okay I do not know a lot about this but what you’re dealing with is a Exhaust Gas Recirculating Valve. The location and whatnot can be found here on this website: http://autorepair.about.com/od/generalinfo/l/bldef165.htm
I hope this helps!

- Kevin