help... what do i have to fix??

[aalugo2000]

ok,
ive had a ses light for awhile now, and when i went and got it scanned at autozone it said:

po420: catalyst system efficency below threshhold(bank 1)

po430: catalyst system effeciency below threshold (bank 2)

my mom had the car at a dealer about 6 weeks ago, he tried explaining to her that it was something about the converter, but of course she knew nothing of what he was talking about, so the info wasnt successfully relayed to me. so im guessin its not just an o2 sensor?? maybe a bad cat?? i think i may have an exhaust leak at the cat too, i can hear noise from there when im driving. when i had the rksport high flow installed the guy at the muffler shop did a really terrible weld on it, maybe thats why its leaking?? but that was about 2 years ago, and ive noticed the noise for at least a year now.

so please help me out... so i just need a new cat????

[shortdog273]

You need an 02 simulator.

[12secondv6]

I constantly got that P 0420 code ALL the damn time.
I had a catco 2.5 inch cat.
I ended up upgrading to full 3 inch mandrel bent exhaust so I replaced the cat.
I now have the 3 inch catco cat.
Since installing this I have NEVER gotten that code again.

Catco cat's are $45
O2 sims are usually just under $100 for 2

[aalugo2000]

ok,
so ill get some o2 sims. and 12sec, you helped me with a thread a few weeks ago.. im gonna get the clear image headers in a couple weeks, which have a 3" y pipe, and i have the borla cat back, so obviously im gonna do it all at once, so do i need a 3" cat or a 3"in 2.5" out? what size is the borla intermediate pipe? oh and what site has catco the cheapest? summit? thunder racing??