2019 AT4 - Mods

Taz56 · October 30, 2019

I have a 2019 GMC Sierra AT4, 6.2L

I bought it brand new in July.

In July I added a Tonneau cover and wheel to wheel side steps. I also had 3M put on the entire front end.

In Aug I had a leveling kit installed and de-badged it.

In Oct I had my dash-cam and my radar detector hard wired and mounted.

In Nov I had a cold air intake and new Cat-Back performance exhaust installed.

In Nov still she will get 20" rims and tires (has 18" stock now) and 1.5" spacers to give her a better stance on the road.

More to come.

Edited November 1, 2019 by Taz56

Ghblue · October 31, 2019

Love it. I have a 20 AT4 black. I have the 6.2, but I’d like to make her sound better. I’ve seen people delete the muffler. Anyone have thoughts on this?

Taz56 · October 31, 2019

Never thought of deleting the muffler, not legal in Canada. But on my 2014 I switched to a "Flo-Pro Twisted" muffler. Sounded GREAT.

Edited November 1, 2019 by Taz56

paulny · October 31, 2019

My '19 AT4 had the GM CAI and catback sport exhaust installed as a factory option. Honestly, it sounds amazing. I get compliments all the time and there is no drone at highway speeds. I don't like an overly aggressive exhaust so this one is perfect. Just something to consider as an option to muffler delete.

truck_newbie · October 31, 2019

17 hours ago, Ghblue said:

Love it. I have a 20 AT4 black. I have the 6.2, but I’d like to make her sound better. I’ve seen people delete the muffler. Anyone have thoughts on this?

Your mileage will vary with muffler delete or just muffler swap. I recommend a full-catback system. At this point, there are quite a number of options for the T1. If the Borla, Corsa, Magnaflow, etc are too pricey for you, you can try the more affordable options. Personally, i recommend the Gibson. It's more of a tamer exhaust but it was only about $500 and i love it.

z1boss · November 1, 2019

On 10/30/2019 at 9:19 PM, Ghblue said:

Love it. I have a 20 AT4 black. I have the 6.2, but I’d like to make her sound better. I’ve seen people delete the muffler. Anyone have thoughts on this?

I have a Trail Boss and I installed an electronic cutout before the muffler and i absolutely love it. No drone and you can make it loud or stock quiet with the push of a button. When it is open, it's very deep and throaty. Sounds like a modified corvette. See my post on this. Instructions are halfway down the page and there are a few YouTube videos.

Taz56 · November 1, 2019

Just dropped my girl off. Cat-Back exhaust and cold air intake are going in as I type this....

Taz56 · November 2, 2019

Taz56 · November 2, 2019

Taz56 · November 3, 2019

275 / 60R20

1.5" spacer

Jmcclure0212 · July 1, 2023

On 10/30/2019 at 9:19 PM, Ghblue said:

Love it. I have a 20 AT4 black. I have the 6.2, but I’d like to make her sound better. I’ve seen people delete the muffler. Anyone have thoughts on this?

I have 19 at4 6.2. Just had my exhaust done. Went cat back true dual straights. . Dual 2.5” pipe 4.5”x12” black tips. Dumped little past rear axle. Had the flat pipe under the trans cut out also has x pipe put in.