I have a Euro Pipe exhaust on my 996 Turbo that is getting on in years. I think the cats are aging and I'd like to remove them. Are there 2 cats or 4 cats? Can these be cut out and then weld in test pipes? From memory, they don't unbolt and it's all part of one complete system. Anyone have any experience?

 

There are two cats and yes they're welded into the system, so you need to cut them out and weld in some regular pipe. It's pretty easy to remove the exhaust from the car if you haven't done it before and should take you 1-2 hours depending on experience and how corroded things are. How many miles are on your car? Normally cats last 100k+ miles, but it also depends on whether you drove a lot of short hops where they never got up to operating temp.

 

The car has about 60k miles so it only gets about 5,000 miles per year. When I smogged 2 years ago, it passed but the numbers weren't that great. This past year the numbers were much worse. I've reflashed the car with a Protomotive tune which is very rich which presumably is shortening the life of the cats.


Replacement exhausts are fairly expensive so I figured I'd simply remove the cats from my current exhaust and put in test pipes for the time being.


Is there anything that needs to be done to prevent a CEL upon removal of the cats?

 

100 cell cats don't last as long as 200 cell cats..
You should have them cut off and have a cat bypass pipe made with a 2.75'' pipe to match that inner muffler piping or you can go to 3'' because gutting them will increase drone ..

 

because your in cali you are going to need cats (or a facsimile) to pass emissions. best bet is to have them gutted so they look operational but empty inside

 

? To pass emission tests in California you need to have a functional cat?

 

https://www.6speedonline.com/forums/...smog-help.html
https://www.6speedonline.com/forums/...t-removal.html

one of the great reasons i live in tn!

 

My car is a tiptronic. A hollow cat will likely lead to a drone and generally don't flow as well as a test pipe.

 

you run the straight pipe thru the gutted cat. flow is fine and it looks like you have cats. tip or manual doesn't matter

 

You will likely not pass the sniff test

 

You will need a secondary O2 sensor spacer. That way the second O2 reads loewr results than the primary. It iwll prevent CEL

 

is this what you are referring to?

http://www.fabspeed.com/universal-o2-spacers/

i have a fabspeed with 100 cel cats sitting in storage that i want to mount soon -- and am worried about a CEL with the 100 cel cats

 

Yes but $150 is stupid.

http://www.summitracing.com/parts/vp...FY87OgodOlMA_Q

You dont need them quite that long although those fabspeed ones might work better.

 

they now visually inspect for cats. no cat(s) no pass test. this is only the beginning. though a gutted cat might fool em as noted above, the sniffer probably would catch it.

 

If I live in that state, I would have a swap out system where I put it on before going to take the test.