Just recently purchased an 08 2500HD LMM Z71 with pretty much every option and have some questions since I am new to diesels. Thought it would be good to have an alternative fueled vechile in the family and is our 4th chevy in the driveway. One thing i have a question on is when i purchased it the dealership was quick to say do not put an aftermarket exhaust on it because it will void your waranty. They said something about some type of afterburner type thing. Is this that regen process i hear about? where can you point me to read about it?

Look in the LMM section and you will find lots of info on the regen. cycle. As for the after market exhaust. There are several on the market that won't void your warranty. They go from the DPF back and they are ported so they disapate the heat properly. Good Luck!!

Welcome, and congradts on the new rig!! You have wandered down to the best source of info you can find on these things. To answer your question: Yes, the reason they tell you not to put aftermarket exhaust is the DPF - diesel particulate filter. This is, more or less, the "afterburner" you speak of. It collects the soot, and when it thinks it's full...the motor injects fuel during the exhaust stroke of the engine - blowing unbrunt fuel into the DPF. It gets so hot in there, it burns all the crap off...no soot. Good luck!! Be sure to post some pics of your truck when you get around to it.