With 100K on the odometer and fresh plugs newly installed, it only seemed appropriate to reward the beast for her faithful service with a fresh set of upstream and downstream O2 sensors, perfectly torqued into a new set of high-flow primary catalysts. She'll definitely breathe better during the next 100K. Here's a shot prior to the install:







Will report more later.

 

Thank you, looking good! You are going to be very pleased with the improved power and sound! Keep us updated!!

Let me know if I can assist you with anything else!!

 

Let us know how it goes. The driver's side should be a snap. The passenger side on the other hand...

 

These Porsche flanges.... I think you'll be alright!

 

I have an exhaust thread out there that shows what kinds of tools I used to remove my original cats.

 

Renaissance man, could you link to the thread on removal of primary cats please. I know i am just missing it but have searched for an hour with no luck.

Thanks

 

I was looking for it the other day as I'm toying with replacing mine too. found it here... https://www.6speedonline.com/forums/...lots-pics.html

 

Thanks!

 

Looks great! I'm sure the car will thank you.

-Luccia

 

will these throw a CEL or pass smog in CA?

 

I think if replacing with the hi-flow cats like the OP you will be fine. If replacing with complete bypass pipes I have seen where people needed to add extensions to the O2 sensor bungs in order to not throw a CEL. Passing CA emissions is a whole nother story. With complete bypass pipes it wouldn't pass a visual inspection although it might pass the actual test.

 

jbuddya is correct but just to elaborate. When replacing the factory cats with our HJS high flow cats you will not have a check engine light and you will pass the sniff test because it is still burning off the unused gas. Although, with that in mind you still will not pass the visual in CA. The catbypass pipes on the other hand are a different story, there is a chance even with the O2 spacers that the check engine light will be on but they do limit it quite a bit. As far as the emissions testing goes, you will not pass the sniff or visual due to California Laws .

Hope this helps, thank you jdubbya for the input!

 

Thank you for replying, Fabspeed!!

Quick question to clarify though, if we're talking about best performance and bang for buck value, and if I were to pick one pipe instead of risking not passing SMOG by buying both the high flow cats and bypass pipes, would I be better off with:

1. Keeping stock primary cats + cat bypass pipes

or

2. High flow primary cats + stock secondary cat pipes

I would be pairing the exhaust mod with a chip, so I'd like to see what my best option is.

Thanks in advance!

 

Even your cats won't pass the visual? That seems pretty absurd. Still doing pretty much just as an efficient job right? Sorry but CA is screwed up.

As for bypass pipes, replacing the secondary set of cats will not throw any codes but obviously still wouldn't pass the CA visual inspection.

Sorry but you are kinda screwed in CA. Where I live in WA I don't have any tests or inspections so "technically" can do pretty much what I want. Like I mentioned though not sure I want the Cayenne to be that stinky if I replace the primary cats.

But...more power is always fun!!

 

Yes, even the HJS 200 cells will not pass and they do an AMAZING job. Technically unless it has a CARB certified sticker on it, it fails.

We are not all that lucky, I wish we were. CA laws make things a bit difficult, just need to find a "performance friendly" shop