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'03 996 C2 - Cats going bad

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Old 04-08-2016, 06:18 PM
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9964ZNG
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Question '03 996 C2 - Cats going bad

So my cats are starting to go bad and I've been looking around for the best deals on x-pipes. Looked at all the usual suspects but then came across Evasive Motorsport offering x-pipes for $855. Seems really legit, right? lol. Does anyone have any experience with them or their products? Seems like it's either a rip-off or a new company looking to get their products out there.
Old 04-08-2016, 07:08 PM
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Vdubjetta02
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My exhaust rattles and sounds terrible below 3,000 RPMS... I have had two mechanics that think my cats are going bad, however I just passed emissions with flying colors...


Just curious, how do you know your cats are going bad? I also have an 03' with 72,000 miles
Old 04-08-2016, 07:35 PM
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Macster
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Originally Posted by Vdubjetta02
My exhaust rattles and sounds terrible below 3,000 RPMS... I have had two mechanics that think my cats are going bad, however I just passed emissions with flying colors...


Just curious, how do you know your cats are going bad? I also have an 03' with 72,000 miles
Doesn't have to be from a bad converter. The noise can be from a loose heat shield or something else loose and making contact with something it shouldn't.

Have you checked for any pending error codes?

My Boxster actually had a loose converter brick -- at the end it knocked when cold and buzzed when hot -- occasionally it would trigger a CEL and error code P0430, but the car could go months without the error code showing up. And the car/engine passed smog a number of times too.
Old 04-08-2016, 07:43 PM
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mcfisticuffs
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I just installed a SpeedTech Catless X-Pipe. It does smell a bit, but my eyes don't water unless I close the garage door on it.

Noise wise - I've got Sports Exhaust mufflers, and at "city" speeds and low rpms, it's hardly any louder (at least inside the car).

At WOT in a tunnel......... it's devastatingly loud above 5k revs.
Old 04-10-2016, 03:43 PM
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crmcgregor
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One of my cats started rattling about 3 months ago on my 03 4S with 64k on it. Savin up for fabspeed 200 cell sport cats... bout $2k for those, better than paying $2k for ONE OEM cat from Porsche. Cannot wait cause the rattle is so annoying.
Old 04-10-2016, 05:04 PM
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San Rensho
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To check if your cats are going bad, compare the voltage of the pre-cat oxygen sensor to the post cat sensor reading. The pre cat voltage should follow roughly a sine wave and the post cat sensor should be close to a straight line. If the post cat sensor starts to show a sine wave, then you have a bad cat.
Old 04-13-2016, 03:28 PM
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Vdubjetta02
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I just passed emissions and don't have to get them for another 2 years... may just be worth going catless for 2 years until I have to swap my cats back in again... I have gone this route with a few of my other cars. At the 2 year mark it just gets slightly annoying changing them out before and after inspection.
Old 04-13-2016, 04:02 PM
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ZuffenZeus
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Originally Posted by Vdubjetta02
My exhaust rattles and sounds terrible below 3,000 RPMS... I have had two mechanics that think my cats are going bad, however I just passed emissions with flying colors...

Just curious, how do you know your cats are going bad? I also have an 03' with 72,000 miles
Do you have the "Sports Exhaust System" option# XLR?
Old 04-16-2016, 06:24 PM
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9964ZNG
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Love how my thread asking a question about a manufacturer got jacked for other people asking about how they know if their cats have gone bad.
Old 04-16-2016, 07:10 PM
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Macster
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Originally Posted by 9964ZNG
Love how my thread asking a question about a manufacturer got jacked for other people asking about how they know if their cats have gone bad.
Um, guilty.

I do not know anything about the manufacturer about which you ask.
Old 04-17-2016, 12:04 AM
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Spinout
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The Evasive system that you linked looks interesting because it has a valve that varies the output of the X pipe. I have never heard of this manufacturer or anyone using them although that means nothing. From the photos the welds look very good. I can attest to the quality and workmanship of the SpeedTech X pipe. I've run this pipe on my 996 for over a year now and just love the way it sounds, especially at higher rpm's. The quality and workmanship is top tier and the price is very attractive. I've never had a CEL using this pipe



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