Performance Upgrade Package

eppieguy · May 3, 2019

I think it should be, what are you showing in the second picture?

Smoothie · May 3, 2019

That just doesn’t look right! Doesn’t seem lined up

bshort · May 3, 2019

7 hours ago, Smoothie said:

That just doesn’t look right! Doesn’t seem lined up

I loosened the clamps and straightened it up a bit.

L86 All Terrain · May 8, 2019

My K2 6.2L, I run a AFE CAI, but with factory exhaust. That way the truck is quiet when I want it to be, and when the engine is under load, you really hear it drawing air and it gives me all the sound I want. On my 2010, I had a Magnaflow muffler installed and you would have a migraine after a 3 hour drive. It sounded great, but it just annoyed me on long drives. If I were to do anything to the exhaust again it would be long tube headers to the stock catback, but have an electric cut-out welded in before the muffler for those rare occasions you want to draw ridiculous amounts of attention.

MG386 · July 18, 2019

How loud is the performance exhaust in the backseat when you are pulling a trailer and the engine is running between 2600-2800 rpm?

This! Curious if it drones with a heavy load and needing more throttle in cruise.

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OnTheReel · July 18, 2019

7 minutes ago, MG386 said:

This! Curious if it drones with a heavy load and needing more throttle in cruise.

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I haven’t pulled anything too heavy yet but no drone with 4000 pounds.

Robwcormack · July 18, 2019

On 3/31/2019 at 8:26 AM, SierraAT4 said:

Ok, so we got it out without cutting it, but this was on a lift with two people manipulating the exhaust back and forth. It takes a little tetris/gymnastics to get it out of there in one piece, but it is 100% doable. On the ground or on jackstands? I'm not sure I would have bothered trying to get it out in one piece.

Of course, once we got it out and realized how long it was, and I had no easy way to transport it (and no real potential to sell it, it's likely going to end up at the recycler), we ended it up cutting it just past the second flapper so I could stick it all in the bed of my truck.

My advice would be to just cut it out with a sawzall, one cut will make pulling the old one out 10x easier. And then the new one goes in exactly as you would expect it to. There aren't any instructions in the box (other than to consult the official accessory service manual, AKA have your dealer do this), but you really don't need any, it pretty much fits together and hangs perfectly. Keep the existing clamp from where the flex pipe connects up toward the front, you'll reuse that one, everything else is in the box.

Did you need grommet pliers to get the hangers out or did they come out pretty easy?

JD Sierra 2020 AT4 6.2 · February 20, 2020

Anyone know if the GM Performance upgrade (CAI and exhaust) requires programming to be updated?

MG386 · February 21, 2020

Did you need grommet pliers to get the hangers out or did they come out pretty easy?

Anyone know if the GM Performance upgrade (CAI and exhaust) requires programming to be updated?

With a little spray of silicone lube on each one, and a pair of channel lock pliers, it's pretty easy to remove hangers. You could probably do it without the pliers.

The ECM program flash is included with the GM intake. I drove around for a few days with both intake and exhaust without the re-program and had no issues.

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bearded_warrior · February 21, 2020

On 7/18/2019 at 3:03 PM, Robwcormack said:

Did you need grommet pliers to get the hangers out or did they come out pretty easy?

I've used a bit of wd-40 and a flathead screwdriver to get them out too. They aren't too bad. Just threaded the flathead through the hanger and used a little leverage to pop them out them. There's lots of videos on youtube for how to remove hanger brackets. Channel lock pliers are another easy way as @MG386 said.

JD Sierra 2020 AT4 6.2 · February 21, 2020

3 hours ago, MG386 said:

The ECM program flash is included with the GM intake. I drove around for a few days with both intake and exhaust without the re-program and had no issues.

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I ordered my AT4 6.2 with the performance upgrade and Dealership is telling me there is NO flash for it. Doesn't seem right to me.

MG386 · February 21, 2020

I ordered my AT4 6.2 with the performance upgrade and Dealership is telling me there is NO flash for it. Doesn't seem right to me.

U could try calling this number, maybe they can check your Vin to see if it was done.

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JD Sierra 2020 AT4 6.2 · February 24, 2020

Will try that. Thanks!

OnTheReel · February 24, 2020

Certainly a chance that trucks ordered with the package would come with the correct software already loaded. I understand the parts are dealer installed but maybe they at least load the correct calibration when they build the truck to save time. If anyone at GM was competent, that’s how it should be anyway...

Supercup · February 25, 2020

My 2019 AT4 Carbon Pro came with cat back, but not the air box. So I picked up an OEM cold air box and asked dealer to do tune also when they installed - they looked at me like they had no idea what I was talking about. I showed them some write ups from GM where it states tune is part of performance package. They said they would look into it.

When I picked truck up they said the tune instructions were in the instructions for the air box install, so the tune was added - so I now have the performance package complete! So if you add OEM airbox, you will get that updated tune!