Could be second carburetor(s) had same problem as first. Hmmmm -- bad idea but could be. But, then, how old is the fuel in your car? Fuel sold in winter months can have different composition than summer fuel that is designed for higher summer temps and old fuel doesn't work well anytime. Relatively recently, bought fuel at Costco in Chandler. My 383 pickup started losing power on the Interstate and backfiring back through the carb. Moved to another fuel tank and regained smooth running and 20 MPH as I held throttle steady during tank change. Anyway, popping back in the intake occurs when a late burning charge in a cylinder ignites new fresh charge in intake; timing, bad valve, lean mixture, flat cam, bad ignition. Warren Anderson Sedona,AZ To send a message to this group, send an email to: Chrysler300@xxxxxxxxxxxxxxx For list server instructions, go to http://www.chrysler300club.com/yahoolist/inst.htm For archives go to http://www.forwardlook.net/300-archive/ Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Chrysler300/ <*> To unsubscribe from this group, send an email to: Chrysler300-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/