In my experience, these engines are a bit funny when it comes to free flow exhaust-there is a point where there can be too much flow. A lot of engines rely on backpressures for certain things and when you take this pressure away, it will result in all kinds of mischief. If you're coasting down a hill throttle closed and it is popping and backfiring, then the others are correct in saying it is the exhaust system. Are you using Alpine headers? -----Dani B. #5003 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/