pretyt much what the title says...how can i tell if my cat is bad?

well i think if it gives u that rotten egg smell after a WOT, thats all I know of, yes im

Discolouration (sign of overheating)
External damage
Clog
Corrosion
Rattling under throttle
Bogging acceleration

It's just easier to jack the car up and inspect it yourself.

hmm i do hear rattleing when im in first and second gear sumtimes could the cat be causing me not to pass smog

I get ratling under 1500rpms and 2000rpms whilie in gear, is this the sound you guys are talking about it. (like alluminun foil????)

yup
yes
it is

i think it has to do with failure of CA smog check...

If it rips up your curtains and ***** on your carpet

I must be mad tired..cause i got that joke lol

if i take the cat off and inspect it, what am i looking for? what will tell me that it is bad?

shedding/anxiety

lol, i agree

anyone have any helpful answers to this question?

when you look inside the cat look for any blockage or broken pieces of the catalyst. if you see any of the above then it's time to get a new one. hope you don't have much trouble getting the bolts off.

Damn i'm getting the same thing. Rattling occasionally around that rpm and before WOT. Would there be a CEL if the cat would be going bad?

when it doesn't use the litter box?

Wow come to think of it i think my cat is bad too :[ Doesnt nissan charge like 500+ for a new cat? Sounds way too high but for some reason thats what i thought i remembered hearing.

Would an aftermarket cat just be better? what would the disadvantages be...

well inspecting the cat was a pretty short lived adventure, the jack i have is a piece of ****...guess im gonna have to take it in and get a diagnostic.

the rotten eggs smell can occur even with a good cat

I would check first the heatshield over the cat to see if that's causing the rattling.

I finally put in my y-pipe in today and I get a small rattling as well as 2 of the bolts holding the shield in broke.

How much is a new oem cat? What are the disadvantages with aftermarket cats...like a magnaflow or something (not a highflow cat)

ehhh....oem is too much...just get a magnaflow hi-flow cat or something...start building up your exhaust...i dont have to pass emissions here...so i gues thats why thats my call

how much exactly does an OEM cat cost?

You also have the option to go with a remanufactured Nissan cat for under $200. This is what I did when my cat went to pieces. PM me if you want more info...