well based on the picture and your description of getting quieter, it's almost undoubtably a failure in the core, with the most likely scenario being it melted down.

When you say little pops on deceleration are you running rich in low throttle conditions? If you're too rich that unburnt fuel is going straight for the cat and would be what caused it to get too hot.

Who tuned you for the vortech kit? I'm positive you've got a problem with your tune, not a problem with your cats, especially if they've both failed.

 

im tuned by jeremy tibbs and mike from AAM no more than a month ago, im positive its not my tune thats for sure...I also have aem uego in my car and it is dead on...4th gear im 11.5 at redline and 11.8 5th gear at redline, cruising around right at 14.6-14.9., never dips below 10.5 at wot..It happens, and has happened before on my srt-4 which melted the cat, unlike this cat which is not melted, it is just collapsed... it just makes me worry about the quality holding up with forced induction...also i have a nismo cat back which has caused other problems for these cats..

honestly the only thing i can think of which i don't know if it makes sense or not...i have heard something like this can be caused from a misfire...well my car has never misfired and has driven perfect knock on wood from the first day it was boosted..The other day, same day this happened i was in 2nd gear rolling and stomped it and forgot i didn't turn my traction control back off after getting gas..bla bla bla and when the tires started to break loose the trac. control engaged and the car fell on its face and then came right back, but it was fine after just normal trac. control kicking in which by the way i always turn off just slipped my mind..so a little while later sounded a little raspy, then later did a pull on the highway smoked a new stang gt and came into town to notice it was quiet and didn't have the same growl...would trac. control kicking in like that be considered something like a misfire? or cause something like that? i wouldn't think so but idk.. wow i was ranting

 

Very possible. Many manufacturers cut power with TCS via massive ignition retard. I suppose with you making more power than TCS would be expecting, in order to cut power long enough to be happy it might have had to work longer than it should have and put you in a prime condition for misfire.

 

it just seems like it would have thrown a code if it misfired, but i guess not if it was just trac. control kicking in...idk...i mean it was just normal trac. control kicking on and off like it would for u or anyone else but i admit it was much harder than when it happened when i was n/a and i can see it resulting in something like that...i always turn the tc off cause it breaks loose pretty easy now and id rather be in control honestly, it was just a stupid mistake not to leaving the gas station after getting gas i guess if thats what happened..

 

I would have thought a misfire would have thrown a code too...but maybe when TCS is triggered, misfires are considered 'acceptable' by the ECU and not logged? Can't say for sure.

 

im warrantied which is good, and i do my own work so its not like i have to pay someone to take them off and on, but the car is down for week or so which sucks..i am gonna give the new ones a try and if for some strange reason it happens again they said i could replace them with their test pipes if i wanted, so if it ever happens again i guess thats what ill do and sacrifice for some rasp....the berk high flow cats do sound amazing !! so clean which is why i am giving it another shot