The muffler heat shield may become loose on the muffler causing a rattle or popping noise. Our technicians tell us there is a kit available from GM to correct this problem.Google+
Car Problem Reports
GMC Yukon XL 1500 Popping Noise From Muffler Heat Shield
GMC Yukon XL 1500 Problem
Average Mileage: 104,750 mi (43,000 mi - 151,000 mi)
Visitor, 2004 GMC Yukon XL 1500, 106,000 mi
The muffler is making a pinging sound when hot....!!!!!
Visitor, 2003 GMC Yukon XL 1500, 151,000 mi
popping and crackling in the exhaust area
Visitor, 2005 GMC Yukon XL 1500, 119,000 mi
major vibration/rattling noise from muffler heat shield at 1100-1200 rpm only. Makes noise in gear or out of gear when engine/exhaust are hot only.
Visitor, 2005 GMC Yukon XL 1500, 43,000 mi
Popping and pinging noise from exhaust system. Not yet addressed.