Bank 1, Bank 2, whats what?

So its looks like i'm going to be replacing one of my cats. my ses light says my bank 2 o2 sensors reading too lean and my bank 2 cat isnt ruunning effciently. i'm assuming this is the bad cat. (i think thats a pretty safe assumtion) so what side is bank 2?
Thanks!!

Not sure but I would try replacing the O2 on your cat first and see what happens.

Bank one is the driver's side.  Bank 2 is the passenger's side.  Sensor one in each bank is before the cat.  Sensor two is behind it.

As ehhget said, a bad O2 can fool the computer into thikning the cat is bad, try the sensor first then do that cat if the problem persists

Don't just throw parts at it.  Parts like cats and O2 sensors are expensive.  A dealer (or other mechanic) with a scantool can check your O2 sensors to accurately diagnose the problem.
 
If you do need to buy cats, you can find them on eBay for about $52 each with free shipping.

Yeah like Ron said probably best to have it diagnosed first instead of doing a crap shoot will save some cash and frustration in the long run.

thanks for the good info all. i believe that my cat is bad because of the loud buzzing noise coming from my exhaust when i'm on the gas. it sounds like a baffold broke lose and is buzzing back and forth or somthing. is that possible??

That buzzing noise could possibly be coming from the muffler too, or are you positive it is the cat?

Give the cat a smack with your fist, if it rattles then the insides are shot

Be careful with the smack test on the cat though.  I did that once and thought it was bad only to learn it was a bunch of tiny rocks vibrating on the heat shield.