curveraider

Hello all,

Does anybody have any secrets for getting to the 3rd exhaust bolt to remove the secondary cat? I am a little afraid to pull on the unit to get a box wrench in there. Is there a special tool I need or do I just need to drink some more cool-aid and bloody some knuckles?

Thanks,

hk_usp9f

Try this one: http://turbo911.com/showthread.php?t=293

tetongolf

You definitely need the half moon wrenches. I tried without, there is just no way, it is way to tight to get any other wrenches in there.


Michael
04 CTT
07 Q7

curveraider

Thanks guys for the postings. The extent of my wrenching is basic oil and brake pad changes... With that said, what is a half moon wrench and where do I get one?????

Shamus

I was wondering the same thing

curveraider

Thanks again! I just placed my order for a set of half moon wrenches

hk_usp9f

Good luck and let us know how it turns out. Are you installing Fabspeed cat bypass pipes?

curveraider

Thanks for the words of encouragement and the advise. Yes, I have had these Fabspeed pipes sitting in the garage for a while and I just never had the time to get them installed. I hope to finish my little project this weekend!!

pzull

Was wondering if cat bypass on cayenne requires any place to reinstall O2 sensor? Asking for a friend who wants to fabricate

User 4221

O2 sensor is not attached to the secondary cat (unit being replaced). The sensors are fore and aft of the primary cats.

You can replace easily with no affect on electronics.

kaizashozay

prepare to hear a rattle sound when u hit the throttle. u can only eliminate this buy buying new mufflers....so i am told. im actually putting my cats back on and will be selling my bypass pipes.

mudman2

Any muffler shop will do it for $100, save your self the bruised knuckles. You will like the result by the way.

pzull

Thanks guys. But why should there be a ratling sound if properly installed and using 16 gauge steel?
I know I did get some metallic sound when I used 18 gauge for headers on old 911 but went away with 16 gauge

Stone43

I am not sure if "rattling" is the right term, but there is something definitely metallic when you hit the accelerator hard. It is my only complaint with the pipes. Otherwise a nice upgrade for a fairly low investment. I have to admit, I have been toying with the idea of a new muffler and tips.....

mudman2

The noise you refer to occurs in ALL S cars if you push them hard enough. It is not Cat Bypass Pipe specific, but due to the faster build up you hear it more.