Having an issue with my gt500

I am having a problem with my gt500 that is beginning to get worse. The car feels
Like it's choked. Especially under load and the boost gauge jumps up and down. I have a sct x4 that I got from Jlt and had to updates done according to mods. I just changed my plugs and fuel filter this week to rule out both maintanence items. Has anyone had a similar issue? Could it be a tune issue, but what is strange it's getting worse.

Sounds like a clogged cat to me.

I wouldn't be boosting the car until you get this figured out. If it is a clogged cat, a lot can go wrong. Best of luck

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Could also be a vacuum leak somewhere.

Check the fuel pressure. Could be a fuel pump going out, ethanol corrosion on the fuel sock / pump, or a fuel delivery problem.

Car has no cars.

Car has no cats

The boots gauge is a vacuum gauge also.you should be able to determine a leak for sure I would think .
Does the boost gauge fluctuate at an idle , or while driving other than in boost ?

No it's not.

what throttle body are you running? if aftermarket could be tuned incorrectly.

At idle boost gauge doesn't move. It only shows boost on factory gauge no vacuum.

Factory boost gauge is inaccurate, it doesn't use actual boost so you shouldn't rely on it.
However, if you're certain it didn't do that before then there could be a problem, I'm guessing belt slip because it sounds like you're loosing boost in WOT.

it might not be even close but i had a similar issue with mine. turns out the cai filter was loose and throwing off the air flow

What year GT500 are we talking about?