Hey all,

I have a US (California) 3.6 996 C2, which I have imported to Germany Problem is, the catalytic converter has totally failed, and I need a new one. They are $2k EACH from Porsche in Germany, and none of the aftermarket options will pass the TÜV.

There are quite a lot of used versions available, but many different part numbers. Does anyone know if they are all compatible? What's the difference?

Here are the parts from the US Porsche parts catalog:

 

Try HJS cats, about $500, these are the ones FabSpeed uses and are OEM on some Porsches.

 

Unfortunately, the ONLY option in Germany is original Porsche cats. No welding in HJS cats, no aftermarket, etc.

 

I'm still stuck on this, but getting a little more info. This comes from the staff at cargraphic:

Anyone have any idea which converters have the lambda sensors in which location? It would be really great if there were a US and EU cat that could be interchanged with each other.

 

One of my 2004 cats started to rattle badly. (don't now if that's your issue or not) They unbolt very easily and come out. I found that one of the honeycombed plates had come loose inside. It could be seen and moved around through one of the oxygen sensor ports.


With some patience, I was able to get the plate back in position and bend down the inner liner to hold it in place. Then I drilled 3 other 3/16 holes and pinned the plate with 2" stainless screws to keep it from moving. I welded over the screw heads so they wouldn't come loose.


They went back in. No more rattle!


Hope this helps.


Cheers!

 

That's great info! My cats do rattle badly, but I also read the post-cat O2 sensor with the durametric tool and they are also not working. I am not sure if a loose honeycomb and poor efficiency are the same problem or not. Any ideas?

 

My loose plate slid right under the O2 sensor. I did get one code and reset it the day before I made the fix. Nothing since then. Sure beats buying new cats!

 

Out of curiosity, how does TUV 'inspect' for OEM-only cats? I can see them having issues with something that obviously looks non OEM, but how could they reasonably identify every OEM vs. non OEM cat for every make/model/year/version of every vehicle they inspect?

For that matter, if they have a database of the 'correct' part number for each cat on each vehicle, would putting any alternative part number Porsche OEM cat do you any good?

 

Well, I think if everything looks normal, and it passes the sniff test, then it's fine. But a brand new, louder aftermarket cat, that's bright and shiny in an otherwise dull, dirty underbody, will draw attention and then looked into further (and ultimately failed.) German regulations are completely retarded - you shouldn't have to have an OEM part if an emissions test is done (or shouldn't need the test if using an OEM part), but that's Germany for you.

I think if the car passes sniff, is normal sound level, has no rattles, and has the OEM form factor then it will pass. That is why I think I would be ok using any Porsche cat - there is no way they can/will go through the effort to find the part number and cross check with the VIN to ensure it's the exact original part. I am confident seeing PORSCHE on the cat, and it fitting my car and passing the emissions test will be enough.

From pictures I have found online, it looks like all part numbers starting with 996-113-03 have the O2 sensor "in" the cat - meaning in the bulky section. Of course, that's what Porsche dealers say my car has, and of course it's the least common and most expensive. From the sonnen oem parts catalog, it looks like that cat fits all 2004/2005 models except the GT3. I guess in 2004 Porsche moved to a single cat for all models?



The O2 "in-cat" sensor for other 01+cats is a good 2 feet away, so I am guessing I am just screwed and have to use 966-113-031-01/02/06 (as far as I can tell -01, -02, and -06 are the same part).

 

That looks identical to mine, not to say the internals are the same. '04 C4S. Has two O2 sensors, one pre and one in the body.