Originally Posted by Child_uv_KoRn (Post 9078357)

I'd be worried about the beginning of the exhaust...

Originally Posted by Prophecy99 (Post 9078607)

enough of that mess man, i took off 184k stock bone dry and totally intact, not entirely sure your experience and repetition of the possible outcomes make that such a common issue.

Originally Posted by Child_uv_KoRn (Post 9078658)

Well, let's see. I owned a maxima that blew up from the cats (75k mi). I own a spec v that had a disintegrating cat (big oil burner from it). I swapped a motor on another maxima with a disintegrating cat. I have a friend with an altima that blew up from the cat.
There's many threads on here with people whose engine blew from the cats or installed headers and the cats were ****ed. Nissan had a recall for the QRs, but just band aided them, so they would last out of warranty (all of them still blew up). Half of the 3.5 maximas/altimas (and ALL of the QRs) on CL are for sale b/c the cat is bad or already blew the motor. There's 1 million links online about blown motors from the cats.

If you drive all hwy miles like a grandma, then it's unlikely to happen for a long time. Quit driving like a ***** and you'll find out.

It is a very real time bomb. You can be in denial all you want, but every engine will be ruined from the cats.

Originally Posted by 5thgendriver (Post 9078673)

and your suggestion for someone new to this platform would be....

Originally Posted by foodmanry (Post 9078678)

Gut your precats and install O2 spacers or sims.

Originally Posted by 5thgendriver (Post 9078683)

thanks for the reply. while I haven't really looked at the entire exhaust setup so I have no idea what's involved in removing the precat. so whats the alternative to removing and gutting the precat and remove and replace it all together? whats needed and approx. how much is the part?

thanks

Originally Posted by Child_uv_KoRn (Post 9078697)

You have to remove the manifolds. The front is easy, but the rear is difficult, especially depending on the rust level. Front precat falls out or is easy to pop out. The rear precat is usually pretty solid and has to be drilled/punched apart.
Or just install headers.

Originally Posted by 5thgendriver (Post 9078715)

ok...I was just looking at the obx header set up for my 01 and looks like the its a 3 piece set up. is this correct? if so, looks like the header on the rear at the firewall (hardest one to remove/install) is welded to the (y-pipe?) or whatever its called. any issues with installing it as its connected?
thanks

Originally Posted by Child_uv_KoRn (Post 9078719)

Oh, I wasn't paying attention to your car. 3.0s don't have cat problems (although they could clog at very high mileage). You can just put on a y pipe and only need to gut the rear cat if you're looking for a little more performance.

The obx is a two piece and that's a little weird, but it does install pretty easy (I did it from the bottom and was able to reach all of the studs). Fitment can be a concern b/c it's cheaply made. I would just do the Y pipe on a 3.0 unless you're going to be doing full boltons.

Originally Posted by RLW001 (Post 9078530)

That appears to be a stock y-pipe. The rear bank goes down, then towards front, then 180 degrees to back.

The y-pipe on left is a Cattman y-pipe, the other is Walker stock style y-pipe. The Cattman is way better performance wise.

https://cimg9.ibsrv.net/gimg/maxima....0f9ba3edab.jpg