Hey guys,

I've lifted the car yesterday and saw that our catalysts section is bolted and can be unscrewed, no need for cutting or welding. What do you suggest I should do for a replacement?

Should I go for straight pipes? If yes, what dia should I use?
Or
Should I get aftermarket racing cats or aftermarket section?

What are your opinions?

 

Are those the cats that make the popping tinny sound? If so I can't wait when the time comes to replace them.

 

That's the third and unmonitored cat, yes you can replace it with a straight pipe, Racingline's y-pipe is the one and only for sale, I know Ghozt on here was taking a poll for possibly making a CXJ one! The actual cats are in the headers, and have O2 sensors!

 

Just a word of caution. Many states require that the car pass an annual emission test. If you live in one of those states you need to stay with the catalytic converters.

 

Doesn't throw a light so I've passed two years in a row!

 

But you still have the two metered cats before the y-pipe, right ?

 

Yes. Three cats total. The third one has been removed by a lot of us here (myself included) by installing the ypipe from RacingLine.

My state does require emissions testing. So technically we aren't supposed to remove any cats. I called a shop to see how much they'd charge to install the aftermarket ypipe for me, and as I was explaining about what the part was and told him that he'd be removing a cat and replacing it with a pipe that didn't have one, he said they can't do the work for me. So it was a job that I had to do myself.

My feeling is that if the two cats still pass the emissions requirements, then I'm not being irresponsible to the environment. As soon as my car fails the emissions test, I'll put that third cat back on and leave it.

 

everything above is correct; you can replace the stock Y-pipe with the 3rd Cat with the Racingline Y-pipe which deletes it - it is not monitored and will not trigger a CEL. I have passed emissions no problem as well with the Y-pipe.

regarding the two front OEM pre-cats, CXJ has his aftermarket HFC's coming out soon which will be factory bolt-on with O2 sensors and will also trigger no CELs.

 

Can someone show me some pictures? I'm getting lost here, where are the front two cats?

 

They are right before the one u can see under your car at the bottom of your engine bay.

 

In your second pic, the top left corner has a light grayish colored object that sort of looks like a basketball. That's one of the catalytic converters. That is connected to one arm of the y-pipe. The other arm of the y-pipe bends around towards the back of the car and is connected to the other Cat, which is mostly out of view.

The third, unmetered Cat, is best seen in your third pic, where it brown and football shaped.

Check out Nissan courtesy parts ... there are schematic diagrams that may help you identify different parts on your car.

http://www.courtesyparts.com/-c-8300...8328_8330.html

 

for reference, there are no aftermarket parts currently to replace the 2 directly under the engine; it'd have to be custom if you want to do anything up there.

 

Thanks for your detailed reply mate.

What I really wanted to know is that what is the job of the red marked circles? and the job of the yellow marked one?

 

Red circles are flex pipes (basically braided steel) which are part of the y-pipe. Flex pipes allow the exhaust system some 'give' as the car/engine moves. Without them you'd be replacing different components of your exhaust pretty frequently. The yellow circle is your third catalytic converter.

 

What do you mean without the flex pipes I'd be replacing different component? Bare with me buddy :P

 

usually on cars with transmounted engines (compare our engine bay with G35's and 350Z's that use the same motor; ours is rotated 90 degrees) the exhaust will have a portion made of flex pipe because the engine rocks forward/back due to rubber engine mounts. when you accelerate and let off the throttle everything moves; the exhaust bolted to it moves as well.

here watch this completely unrelated OLD video of my car on a dyno. watch the engine as it accelerates. imagine your entire exhaust moving with that, lol.

 

Some interesting information there!

Alright let me get this straight, so if I go with this part (RacingLine Y-Pipe LINK)


Will it be okay? or will I need to do regular maintenance on the exhaust system? And does this Y-Pipe actually make a difference in terms of lower-mid range power?

 

*Bump*