JCR-Porsche

Our manifolds are without cats. In regards to how much is replaced, we’re discussing the manifolds but the same can be said for any / all of the exhaust system, again in our experience.

JC

erko1905

As risky as catless headers may be from a warranty standpoint, I feel like cats, OEM or aftermarket, are designed with street use in mind and are not a great idea for cars that see significant track duty, spending more time at higher revs. Track cars not running cats might actually have decreased the odds of engine problems in the long run.

A few cars that run w us at PCA (admittedly not 991.1/2 Gt3s per say, but bmws and older porsches) had engine failures that were attributed to cats getting clogged up causing too much back pressure and/or overheating and causing heat problems due to proximity to engine etc.

The other thing I wonder is, is noone going to continue owning these things after the warranty expires?

Bxstr

My understanding was always a catback exhaust is fine. But when you start getting into the emission system or headers you are possibly risking warranty coverage on an engine.

Underblu

How often do aftermarket headers cause engine failures? It would seem there would have to be a clear case of causation between the non oem part and the failure for the warranty claim to be denied. The Munson-Moss act was enacted to prevent manufacturers form denying claims based on the mere use of a non oem part. The nature of the non oem part itself shouldn’t matter be it a performance header, tire or air filter. What does matter is if the part Itself caused the failure.

I don’t know if there’s anything in Munson-moss that deals with the non oem part being a contributory factor. For instance, say a car with upgraded tires pulled high Gs on a race track resulting in oil starvation. Is the starvation due to: the tires, a design flaw within the engine, or both.

Christian Plyler

Yes, I appreciate the distinction. That's why I said that if they can make some connection between your aftermarket part(s) and the warranty claim, they're right around the Act.

Christian Plyler

There would have to be a clear case of causation presented to a court in order for them to win. There only has to be a perception in the head of the decision maker to deny your warranty and make you go through all the trouble of seeking that time in court.

mafoofan

Practically speaking, it’s not a question of who would win in court if fully litigated. It’s a question of whether you’ve got deep enough pockets, enough time (years in all likelihood), and the psychological fortitude necessary to fight it out after Porsche first denies your warranty claim. They know that too. Who’s right or wrong on the matter of causation is not the gating issue.

mdrums

ok gottcha... yeah the mag moss act didn't work for me with the Tubi cat back ordeal and i got schooled on it by the Porsche Zone rep.

RS911

Exactly, not to set a precedence they should contest all claims with a major exhaust change. And at the end should it go to court, the one with the deepest pockets will win.

fxz

Porsche refuse to buy used Porsches that have any mod to the exhaust as they are obliged to resell it with a minimum warranty authorized after local inspection and recorded at Porsche AG and worldwide valid

that is a modified exhaust void the warranty
and the only way to solve this is to cheat Porsche AG through your local porsche dealer reinstalling, without mentioning it, the original OEM exhaust Period

Christian Plyler

I am aware of at least a few GT cars traded in to dealers with modified exhaust systems. I've traded in my own 2018 GT3 with a GMG center muffler delete. In fact, I had purchased it used, CPO from a dealer, WITH THE GMG PART ON IT. In another case, Porsche removed the aftermarket headers, replaced with OEM, and CPO'd the car.

fxz

Cheating the rule is always doable but doesn t change the rule

Christian Plyler

True.