16851 has a hollowed out cat, and it does have a bit nicer tone to it. The car is abit peppier with the hollowed out cat compared to my stock cars 2524 & 16634. The stock cars you can barley hear run, but 16851 does have a nice unique tone to it. I like it, and since we don't have emissions where I live, I'm keeping it that way. -Joe O'Brien 2524, 16634, 16851 To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/