Hamlet

my flex pipes are gone and need to be repaired. The shops I have spoken to all kind of shake their heads, big job. What I think has to be done is to replace the catalytic converters with flex pipe attached. 02 sensors replaced as well. It seems the price for new would be bout $550 per cat. I assume the cat is bolted on but the flex pipe needs to be welded?

I searched the forum found a little info but am still confused. Got some good help in an earlier thread diagnosing the problem. Took it into to a specialty shop with a one eyed 40 year exhaust vet...big job he said.

Original owner of 2004 cayenne s 110k miles, engine was replaced at 30k by Porsche, valve problem.

Anyone done this?

touareg

Sounds like the problem I had on my 2004 Touareg V6, dealer want 2 Grand for new cats plus cost of O2s if I wanted those and said the engine had to be dropped, I had an independent cut/wiggle/weld in there and install a new flex pipe for around $500 (mostly labour). They were going to try to replace my 02 sensors, but was too difficult with everything in place. The flex pipe was the piece below the #15 nut/bolt

Probably doesn't help you as you have a V8, but if it was me, I would pull your current cats and have new flex pipe installed and replace the 02s. If those cats can't come out easy, replace the flex in place. A lot of places are hesitant to do this because technically you are tinkering with the emissions systems (cat) which I am assuming is illegal just about everywhere in the US, not sure elsewhere. Reality is you are just replacing a pipe welded to the cat and not messing with the cat itself. If you don't live in a place that does physical inspections you will probably be OK. Any go fast cheap car muffler shop will probably do this work for you in place if it can be reached. https://rennlist.com/forums/porsche-...***-pipes.html you can see the flex pipes going up, so there might be room under there. Also I had the secondary mufflers removed after the cats.

steve_Cayenne

Had a vibration on a 2013 v6, because of the flex pipes. Here is what the work order said for the warrenty work:

Both flexibles too soft, causing the vibration.
Remove plastic engine cover.
Remove heat shields blocking headers.
Remove 4 O2 sensors that are seized.
Use heat torch to remove 6 nuts on down pipe.
Put vehicle on lift.
Remove panel under engine.
Support engine and transmission.
Remove transmission support and drive shaft between transfer case and front differential.
Remove collets with grinder since they are rusted.
Undo down pipe supports.
Remove downpipes.
Install new downpipes.
Re-install all removed pieces.
Re-connect and wire O2 sensors.
Test vehicle.
No more vibration.

Parts:
POR 95811302162
POR 95811302261
POR 95511111340
POR 95511111340
POR N10209077
Labour: 4.4h

Seems to confirm it is complicated (and that is on a new vehicle with minimal rusted and seized bolts), and that is for a dealer that knows the vehicle. I would be worried having some muffler shop hacks removing parts of the transmission! Not sure if this would be similar for your case.

Hamlet

Thanks for both replies. Both are nicely detailed and helpful. The last thing I want is to feel like I have been snowed when I go to the shop to get this done.

From what I have been able to gather, the whole pipe including the cats will have to come out then the flex pipes will be removed. I am going to get replacement cats with flex pipe attached and 02 sensors. This is a ten year PIG, drives great, I like it and want to keep it on the road for five more years. I assume i will have to spend 3k a year on maintenance/tires and that is ok. Last thing I want is to do this over again cause the 10 year old cats go.

I figure this will cost me close to $1700 for parts and labour, looks like I can get new cat with pipe for 500 ea and around $100 each for new 02 sensors. I am going to try and get my local cayenne Indy guy to do it. Will post progress and pics, this is going to be an age related problem for cayennes.

Shawn Stanford

Mine went last year. I had my indy do it using the Touareg part.

https://rennlist.com/forums/porsche-...-an-05-v6.html

https://rennlist.com/forums/porsche-...pe-repair.html

Hamlet

Thanks Shawn, mine is v8, I will check to see if there is the same part.