Dual exhaust warranty

[AFinz]

I have a 2018 Sierra 5.3. I went to the muffler shop the other day with it in mind that i would be running dual exhaust from each cat. I didnt realize that it y's into a third cat. The guy at the shop said cutting behind that would void my warranty. I had them put on the cat back from the third cat but im really wanting dual pipes with an x pipe to 2 magnaflow mufflers. I know its a big debate whether cutting this other cat off and running duals would void your warranty. What are your thoughts? Experiences? BTW i did search the topic but there are 193 pages in the main thread to go through if i want my answer. Thanks

[Racindave]

My service rep says it possibly can void the warranty ... they have to prove that’s what caused whatever issue though. Me personally i didn’t touch the 3 cat. Just did basically a cat back dual exhaust. I figured any minimal gains would be negated with the risk and not worth it. 

[bakeronenine]

I was told it would void your warranty, and it's quite illegal. My shop wouldn't even consider it. I have dual flowmaster super 10's out the sides, sounds great. Burly nasty cold start, raspy under full throttle, but you dont notice it at cruising speeds.

[FlipZ71]

15 hours ago, AFinz said:

I have a 2018 Sierra 5.3. I went to the muffler shop the other day with it in mind that i would be running dual exhaust from each cat. I didnt realize that it y's into a third cat. The guy at the shop said cutting behind that would void my warranty. I had them put on the cat back from the third cat but im really wanting dual pipes with an x pipe to 2 magnaflow mufflers. I know its a big debate whether cutting this other cat off and running duals would void your warranty. What are your thoughts? Experiences? BTW i did search the topic but there are 193 pages in the main thread to go through if i want my answer. Thanks

  I'm sure if you had an issue later on , dealer would use it against you.... 

  I set mine up the same way...  cut the mid pipe before the 3rd cat , ran 2  2.75 pipes , 1 X pipe , straight out back with 2 Flowmaster FX series mufflers .... 

   Sounds great...

[kennerz]

Depends what state you are in. In most smog Nazi states anything modded before any factory installed cat is illegal. Do whatever you want after the cats. If your in a state where it's not an issue doesn't make any difference.