ok well about 2 weeks ago my CEL came on, i went and got it scaned and while i dont remember the exact code the readf out was catalyst efficency low bank one. Now around the same time that happend my car started running realy rough at idle, i have tranny mounts theyve been in for a while. the car runs fine everywere else i havnt lost any power i did a quick pull against my friends dsm last week and we were neck and neck like always.gas milage is fine 32-34 cruising, no smoke from the exhaust everything points to the car being fine. oh and i can all of asuddon hear my intake under non boost acceleration its loud and sounds like a turbo i have checked for vacume leaks but couldnt find any. i have an injen cai, vibrant header + dp highflow cat for 15k miles, corsa catback for 5k miles. and oh yea i have a 2006 ss/sc with a custom tune by pual (06blackg85ss). im thinking it may be something with the tune but i cant be sure and hes been really busy lately so i havent been able to meet up with him to look at it. i may take it to cobalt addiction tomorrow since there shop is only an hour away from me.
anyone have anyidea what might be wrong is it somthing i should worry about or what

edit i also want to add the the rpms are not bounceing around they stay right at 800rpm just over the 750 mark. the way the cat vibrates you would think the rpms are moving bc you can feel it in the seat get faster or slower but the tack stay steady between 800 and 900

 

I hear the high flow cats are on the edge of the usefull range so as your O2 sensors age they will most likely throw a code for the cat.

I pulled this off ZZPerformance site regarding the high flow cats they use in their downpipes:

"***IMPORTANT information concerning High Flow Catalytic converters*******

The downpipes we sell come with a Magnaflow high performance converter. It is OBD2 compliant but it is on the very edge of being so. The PO 420 code is set when the rear bank O2 sensor PCM thinks that the converter is not doing a good enough job. Because the stock cat is so thick and dense, it can still function when the tune is off or it gets old. The Magnaflow isn’t like that. An error in tuning, running too rich, having too cold of a Tstat, too cold of plugs, or an old primary O2 sensor can all affect the engine enough to set a code when using the Magnaflow cat. This code DOES NOT affect the way the car runs, it just sets an SES light. To fix it, you’ll need that code removed from the PCM, or you can run our O2 emulator(not available for ALL vehicles), or you can clear the code and try to tune the car in better to allow the cat to operate more efficiently. This is a situation in which your cars stock sensor was not designed with your performance goals in mind. Please make your purchase with the understanding that over time, an SES light could be thrown due to the reasons stated above. This is not grounds for a warranty claim, as a repair or replace of the cat/downpipe would not permanently fix the code."

Though I don't know what cats vibrant use, but this may still hold true for them.

 

thanks for the info im guessing the cat might just be old idk im not worried so much about the code but more about the vibration that im getting at idle