Hello all, I'm a newbie to this site, contemplating a return to the GM fold after an abscence of 15 years. I have a question regarding the reliability of the cylinder shutdown system on the 5.3L engine. I had a really horrible experience with a Cadillac Eldorado with the old V-8-6-4 system, and I'm scared to death of the thought of another similar deal. But wifey wants an Envoy Denali. So, the question is, what are ya'll experiencing? Can it be decativated electronically by means of a chip or some other device? Any real world experience and/or advice would be most appreciated. Thanks so much ya'll....