One (or 2) of my cats on an 02 maxima up front are going back (material breaking up). I can hear it once a month or something where it rattles in park or if parked facing down a hill or something.

My question is what the best options for actually fixing it? So far it seems to be:

1.) gutting the cat and putting back

2.) aftermarket headers (does this actually get rid of 1, 2, or all 3 cats?

3.) y pipe? (i don't understand this one yet. and what cats would this remove?)

i bought a test pipe off ebay and it seems to only get rid of the last big bulbous "thing" in middle of the car. I would call it a cat but when inspected it didn't have anything in it. it was just a big rusted pipe shaped like a small basketball. But i'm sure this is the last/3rd cat? I didn't put it on because while 3 screws bolted up the last we couldn't get so I plan on taking it to a muffler shop later next week.


what do you guys think?

 

there are two pre cats off the headers, you can gut it but it will get loud. Aftermarket headers also delete the pre cats.

like stuntman's max

 

yeah that's a nice sound. But the question is this.... If you DO get headers and get rid of the 2 pre cats, what happens to the O2 sensors and the readings inside the car? Does the SES light stay on permanently? And how does the ECU/everything else know to run correctly without the precats? I figure headers are straight thru without any ceramic honey comb like the original cats have.

plus he seems to have quite a bit going on there:

 

If you decided to get the header, you would most likely need O2 Sims and or non foulers.

 

My secondaries have never thrown a code and I have headers. 95k/9 years