GT3SanDiego

One of the catalytic converters on my 2004 GT3 has failed and needs to be replaced. My local dealer is quoting $2600 for a replacement which I think is crazy expensive for a cat.

The two main options I am looking at are:

1. Buy a Porsche certified cat from Sonnen Porsche for $1254 and install it myself. Has anyone had experience installing these in these cars? It does not look too difficult.

2. Buy an aftermarket 200 cell sport X-cat from Fabspeed which are going for around $2400 for both sides. These are more expensive but are claimed to increase HP and exhaust sound a bit. Since I am in California, they are technically not legal. However, I have heard that they do pass emissions in California as long as the smog station does not visually inspect the cats. Has anyone had experience with these or other after-market cats in California?

Any advice or input would be appreciated.

pmkazz

I do not have a GT3 but have a 996 with full Cargraphic Exhaust, which includes 200 cell cats. It has passed emissions everytime, however, the first 3 smog stations I went to crawled under the car and informed me that they would have to fail the vehicle because the exhaust system component's were not CARB certified. I was lucky and found one station that did not crawl under the vehicle to check for the CARB label. And they passed me twice. So, be cautious as CA is worse than ever with non-certified exhaust components.

mooty

LA dismantler or parthaven?

Spyerx

You verified the cat is bad not the o2 sensor?
If not do that first.
In ca smogging with non oem stuff is just asking to fail. Sometimes they check. Sometimes they don't.

black04

If you just need to get your registration, disconnect and reconnect the battery before you go to the smog shop.

GT3SanDiego

Thanks for the info, the last time I took my car to my local smog station I did not see them check under the car so I am hoping I can get it passed there if I go this route.

GT3SanDiego

I am a little leery of a used cat since they may not have much of a guarantee if they fail to pass. They also did not have anything available on their website but I will call to see if they have something.

GT3SanDiego

I have checked and cleared the codes half a dozen times and the Cat converter code keeps coming up, no O2 sensor codes appear. I have also had this double checked by two local Porsche mechanics and they did not find any issues with the sensors or exhaust leaks that can cause a cat code.

porschedog

Move to Florida. No emissions checks.

cgfen

Why would you do that?
In CA that is pretty much a guaranteed way to fail the readiness monitor test = no chance to even start the sniffer test.

Craig

cgfen

OP, I passed CA smog 2X with 100 cell cats on a .1 Turbo I used to have.
200 cel cats most likely WILL pass sniffer test.
Little likelihood of failing visual inspection IMO.

Cheers

Craig

ps, Fabspeed products ALWAYS increase HP, just ask them.

Spyerx

If the error is the cat efficiency error swap the post cat o2 sensors left right and see if the error follows the change. Assuming you are getting error in only 1 bank.
If this hasn't been done this is always first step. $150 for a sensor vs a lot for a cat.

black04

Hmmm. Are you saying that 1) disconnecting the battery erases the codes but 2) there is some other code that informs the tester that the codes have recently been erased??

I did the battery disconnect here in Los Angeles last year for a different car with check engine light and bad converter and it worked.

That would be good to know if I decide to register my GT3. Thanks.

Spyerx

Absolutely. If you erase your codes and the emissions readiness codes are not yet set, you will fail smog.

Depending on the car, there are about 8 readiness codes that must be set to "ready" to pass the ODB II smog tests in CA. For a car with ODBII they plug into the computer, read the readiness codes, compare those to what SHOULD be ready for the car (i.e., if you have a tune that disables a code, you'll probably fail) and a visual inspection. They do not do dyno tests anymore here for ODBII cars. Old cars, yes (like my 89 and 91).

Any inexpensive ODBII reader with Emissions readiness checks can tell you if these are set or not. And some, take many drive cycles to set. Like EVAP.

4porsh

I agree with what Spyerx said. I recently did many many "special" drive cycles with a OBDII ready hooked up and I still need to find a Indy Porsche shop and pay $ to have the use special computer to put my car in a ready state. Then quickly, but not too quick get over to smog shop for the test. Not fun.