2k3 Exhaust

Quick question for those of you who know about exhaust systems, what the best sounding/value dual or single exhaust system that I can get for a 2k3 Silverado Z71 ext cab, I had asked one mechanic and he said that I probably won't be able to get away with Dual exhaust because GM started to put O2 sensors after the cat now and I'll keep getting check engine errors if I put on dual however he wasn't entirely sure. If anyone has put exhaust on a 2k3 silverado please tell me how it is, what it ran you, and how much of a boost did it give to your performance. Also if at all possible I would like to obviously NOT void my warrenty haha, so any tips on that would help too. Having talked to my dealership they said if any aftermarket products are put on and a problem occurs related to the product then they won't warrenty the work for that problem

I have a regular cab 2003 with the 4.8. I put a corsa stainless steel exhaust on the truck. It was the only exhaust system I could find that did not involve cutting of any existing exhaust pipes. It sounds absolutely fantastic! It took about 2 hours from start to finish with very easy instructions. It is also the only exhaust system that is GM certified so it will not void your warranty and you can order them from your local GM parts dealer or go to corsa-perf.com.

Ive heard of some dealers not fixing clutch problems because of an intake so "Related" is kinda a loose word

straight pipes give you the best preformance and can be done by most muffler shops make sure they use Mandrel bends though.

Ive heard nothing but good things about borla i cant say much about flowmasters exept - redneck icon and cheap

I have a 2003 Silverado ext 4x4 @ 700 miles, I had the org muffler cut off and I had a Flowmaster 40 series muffler installed. All of the org exhaust stayed on the truck. The shop had to add about 8" pipe since the flowmaster is shorter. A friend of mine did the same thing to his 2003 Silverado as well. Great sounding truck, it sure does turn a lot of heads.

Dan