fpena944

Aside from the rattle mine got so clogged I couldn't rev past 4k RPM. I would get a CEL each time I tried.

Another thing I noticed when I switched over (and this could just be because again mine were clogged) was that it takes a little higher RPM to launch the car. So it almost feels as if the car lost a touch of low end torque when I upgraded. But it does feel more powerful at higher RPMs than before. Just an observation though, don't have any before and after numbers to back it up.

Macster

The noise may not be from the converters. It can be from the heat shields or something else "back there".

If there hasn't been a CEL with a converter error code (P0420, P0430 to list 2) I'd hazard a guess -- no bet though! -- the noise is *not* from the converters.

My 02 Boxster had a buzz and while I hoped it was just a heat shield it proved to be a converter.

However, I hoped against the odds as my car's converter, the loose one, every once in a great while would trigger a P0430. What would happen is the loose brick - the source of the noise -- would shift out of position slightly and this would affect the exhaust flow through the brick and the CEL would come on and I'd pull the P0430 error code.

As long as the engine runs ok, as long as the CEL stays dark (and if it does come on offers up an error code that points to a bad converter) you might just take a wait and see attitude. I drove my Boxster with the converter problem quite a few years, but the car always managed to pass emissions testing, though this last time took some extra effort.

davemonfl

Has anybody on here done this? I have a 2007 base Cayman with bad CATs and was considering buying high flow Magnaflow CATs and having them wielded in. Does anyone know the dimensions of the stock CATs at the fattest point? The exhaust pipe is 2.25", right? Do the CATs have to have 2.25 inlet and outlets or 2.5 to fit over the exhaust pipe? Sorry for the dumb questions. The oxy sensors are mounted before and after the CATs so they should still be in place, right?
I have had resonators removed on an '03 VR6 Jetta and an '09 2.0T Jetta by the same local shop and they had to fabricate a bent pipe to replace the resonator on the 2.0T. I have been very pleased with their work on those two cars and would trust them to do the Cayman.

kromdom

Have you also tried asking here: https://rennlist.com/forums/porsche-...nerations-126/

davemonfl

Thanks I will do that

hotelguy

I had the Fab speed x and 200 cell cats...on my old 4s. They were great no issues....

I have my old cats for sale if anyone needs them off my 2003 4s.

davemonfl

That being said, has anybody here in the 996 forum purchased aftermarket high-flow cats and taken the factory cats to a reputable fab shop and had them cut out the factory cats and replace them with the after market CATs?

kromdom

I purchased CARB-legal cats by Magnaflow, direct bolt-on (no fab/weld/cut needed). Also had bungs for O2 sensors.

Look here to see if they have one for you Cayman: https://www.magnaflow.com/catalytic-converters/

Best of luck

davemonfl

Thanks for the reply. Have you had them on for a while and no issues or CELs? They do have those Maganaflow bolt ons for the Cayman at about $400 a piece. Of course then I'd have to pay to have them installed too. I read a post from one guy that said it should only cost about $500 to have a couple hi flow CATs welded in place of the OEMs at an exhaust shop and thought that might be a good way to go since the CATs by themselves are less than $100.

kromdom

No issues/CELs, etc. thus far. Plus Magnaflow offers a 5 yr/50K mile warranty

davemonfl

That sounds like it might just be my best bet. Any recollection of install cost or did you do it yourself?

kromdom

Magnaflow requires installation by a shop to keep the warranty. My local indy charged $145 (passenger side) and $200 (driver side).

Bought the cats from HOTTEXHAUST.COM (free shipping, authorized dealer). Ask for a 10% discount coupon (saved over $200 for both). Best of luck.

davemonfl

Wow, awesome. Thanks for all the info!

rattlsnak

I did some research on a mfg number I found on some cats offered by various companies and found the company that makes them.

go here: http://www.discountconverter.com/

I know the name sounds shady, but I've used them on three different P- cars now and they are great.

Roughly $340.00 per side shipped.

davemonfl

Thanks I will see if they have one for the Cayman