Denali21

GM offers Borla exhaust as a performance upgrade option.

I just discovered the same problem on my 2000. It’s a shame I didn’t find it until it rotted out my rocker panel. Like you, I replaced the windshield. It didn’t fix it. Tried replacing the door seal. That didn’t work either. I finally took it to my brother in law who’s a great body repair guy. He opened the drivers door and gently poured water from a pitcher on the roof at the door seam. Sure enough, it was leaking along the front of the door jam seal. It was running out the bottom of the seal and onto the floor (under the carpet) and under the rocker cover. It was impossible to see unless the drivers side door was open. The final fix was that he put some goop behind the seal called strip caulk, and sure enough, no more leaf. It may not be your issue but it worked for me. Good Luke.

Very true. I’ll check with my dealer just for kicks. That’s again for all the helpful advice.

Would really like to but I’m a little hesitant since my truck only has about 600 miles on it and I’m sure GM will screw me on my engine warranty if I install a SC.

Great post. Thanks for the info. I’m looking to install a Whipple SC on my 2021 Denali 6.2 and you guys addressed some of my questions as well.