Get a Haynes manual forget Chilton junk. Or go to the auto parts store and flip through theirs. In the meantime, if you are looking at the EGR valve it is just to the left and under the EGR valve. I had to replace mine last year, easy to do. You are probably getting a check engine light? I had to replace EGR, VSV, and front O2 sensor at the tune of about $500 in parts, ouch! But hey, now I get 3 miles more to the gallon and can legally pass smog

I wouldn't get a used, mine lasted to 120k and they started shorting out electrically. I would get the cheapest price of the internet and then get your dealer to match it, which they do.