I am newbie here. I own two Nissan products, 99 Pathfinder and 97 Maxima. I found this site while doing some search on the Internet. I had "service engine soon light" on in my maxima. I took the car to my reguarl mechanic, who kept the car for week (kept saying it will done tomorrow) and didn't fix it. Took the car the dealer and the dealer is charging me $592 for fix "knock sensor (P0325)" and "purge control(P0443)". I think I am getting ripped off, but it's too late now. I wish I had gone to Autozone for diagnostic, and then take it to the mechanic. Anyway. I hope to learn more at this site about my max and pathfinder before taking to mechanic for repair.