Hi all ~ I did the unthinkable ... while changing the plugs on the 4.2L engine on my 06 Envoy, the #2 plug broke in half with the threads remaining in the engine. I'm not a mechanic by trade so changing oil and plugs are the only thing that I would even attempt on my own. This is the first time that I've run into an issue such as this in the past 20 years and 3 vehicles. Would one of the experts in this forum reply back with thoughts on all of the possibilities of issues as well as suggestions of how I can resolve them ... and ultimately what I'm facing as far as costs are concerned? ~ Thanks in advance for any feedback on this.