My 924 carrera gt just arrived!

[AaronM]

Originally Posted by mreid

States regulate inspections and vehicle emissions.

States do NOT have exclusive control over emissions rules. States are only free to enact regulations that are more stringent than federal rules. Anyone who tells you otherwise is either lying or severely misinformed.

Look, I'm an attorney. Understanding the law is what I do for a living.

It is illegal to remove a catalytic converter from a car in every state because it's a federal law. Just because a state stops requiring inspections does NOT mean you're free to remove emissions control devices under federal law.

The only time it is legal to remove a catalytic converter is when it has worn out and you are replacing the worn-out unit with a new, EPA-certified, unit. Any state law that says otherwise is invalid because it is in conflict with federal law and federal law controls.

All that said, speeding is illegal too. People take risks all the time. If you believe that the risk of getting caught is small enough that you'll accept it in return for not having a catalytic converter, that's your choice. But don't pretend for a moment that removing a catalytic converter is ever legal.

[mazdaverx7]

That car is so rare and original that I wouldn't modify it one bit. Its absolutely stunning. Why not just enjoy the car the was it came?

[jwmc1]

I hate you a little

[Rasta Monsta]

No need to remove the cat. . .at this age, depending on mileage, there may be nothing in it.

There are several aftermarket solutions for the 944 (same rear portion of exhaust) that will make the car louder.

[Dave Colangelo]

In NY they wont check emissions on anything older than 25 years (all my Porsches and none have been check in NY ever). I am no lawyer but it does appear that the EPA forbids the removal of a cat and considers it "Tampering" however the reality of the mater is that unless you have an EPA agent (if those exist) living next to you there really is no way for them to realistically find out. They are not going to start looking under every loud car out there to see if the cat has been removed... ...are they?

What you need to make sure you do is keep the noise level in spec. I think its 108 DB, this is something that cops will give you a hard time about and the issue is that its somewhat subjective (and I have had this issue back when I raced formula cars that were checked for noise levels). The placement of the DB meter will drastically change the reading, most people will try and get it as close to the tailpipe as possible but heat can be an issue in this. Even the angle of the meter to the tailpipe will matter, further more a slow to respond meter may give you a different peak reading than a fast meter (due to the harmonic nature of an engine running).

[AaronM]

Originally Posted by Dave Colangelo

In NY they wont check emissions on anything older than 25 years (all my Porsches and none have been check in NY ever). I am no lawyer but it does appear that the EPA forbids the removal of a cat and considers it "Tampering" however the reality of the mater is that unless you have an EPA agent (if those exist) living next to you there really is no way for them to realistically find out. They are not going to start looking under every loud car out there to see if the cat has been removed... ...are they?

This is pretty much what I was trying to get at. But it's important to know what you're risking when you make those decisions. And, technically, a mechanic is not legally permitted to allow a car without a functioning catalytic converter to leave his or her shop. So, in theory, if he took the car to a mechanic and the car did not have a catalytic converter at the time, the mechanic could hold the car and force the owner to install a catalytic converter.

Whether any classic mechanic is likely to actually do that is another story.

I'm not against removing the cat on an old car. I've heard stories, of people removing the catalytic converters from 944 Turbos and still passing tailpipe emissions tests. But I'm not a fan of people making choices based on bad information.

Everyone breaks the law at some point. I speed. A lot. I accept the risk of a ticket. The fine for removing a catalytic converter is $2,500, which is a relatively small amount, as federal fines go, and the chance of discovery is low for most owners. So I can see how some would decide that the risk is acceptable. That's fine. Just go in knowing that you're making that choice.

[Dave Colangelo]

Originally Posted by AaronM

This is pretty much what I was trying to get at. But it's important to know what you're risking when you make those decisions. And, technically, a mechanic is not legally permitted to allow a car without a functioning catalytic converter to leave his or her shop. So, in theory, if he took the car to a mechanic and the car did not have a catalytic converter at the time, the mechanic could hold the car and force the owner to install a catalytic converter.

Whether any classic mechanic is likely to actually do that is another story.

I'm not against removing the cat on an old car. I've heard stories, of people removing the catalytic converters from 944 Turbos and still passing tailpipe emissions tests. But I'm not a fan of people making choices based on bad information.

Everyone breaks the law at some point. I speed. A lot. I accept the risk of a ticket. The fine for removing a catalytic converter is $2,500, which is a relatively small amount, as federal fines go, and the chance of discovery is low for most owners. So I can see how some would decide that the risk is acceptable. That's fine. Just go in knowing that you're making that choice.

Whats also interesting here is that I have spoken to a few mechanics who don't seem to know of this rule. Maybe they did a poor job circulating the info or maybe they just forgot who knows. But either way I agree and totally understand what you are saying. I was just throwing in some NY state experience that I have had over the years. Then again that is just the shop I happen to go to, I cant speak for all the shops in the state.

Regards
Dave

[philt68]

i didn't realize this was going to turn into an in depth discussion of catalytic converters!..

leaving aside that controversial topic for a second, can anyone recommend a good exhaust solution-i'm not looking for it to sound like a formula one car, but at the moment, it sounds as though i'm driving a dyson vacuum cleaner (but slightly more exciting..)

[kcoyle]

Originally Posted by philt68

can anyone recommend a good exhaust solution

No personal experience but as Rasta said there are many 944 options and the turbo "cat back" should be a direct bolt on as it has a 4 bolt flange like our cars. The 944 NA has a 3 bolt flange.

See here for a 931/944T exhaust comparison.

924Board.org :: View topic - 951 cat back on a 931

Exhaust examples.

EXHAUST / RELATED at LINDSEY RACING - Your Porsche Performance Parts Center

[djnolan]

Originally Posted by Rasta Monsta

No need to remove the cat. . .at this age, depending on mileage, there may be nothing in it.

I once had the catalyst break free and it was obstructing the exhaust and it ran very badly. I dropped the rear pipe and removed the obstructing catalyst biscuit. The car continued to pass emissions and run fine after that. I have no idea if the hollowed out converter performed (HP wise) any different than a straight pipe. But certainly nobody could tell the catalyst was completely inoperative.

[Dave Colangelo]

The PO of my 944 replaced the end piece and muffler, not sure who makes it but ill check when Im near the car again. Its a tasteful mod nothing to nuts. It adds some nice low end to the car. The one thing to watch our for is that high pitch honda civic rasp. I have seen a few 944's in passing that had the better part of a soda can welded to the end of a terrible muffler. The sound is reminiscent of putting a baseball card in your bike spokes. If you can try and get near some local 944's and hear them. Where about in NY are you, I keep my 944 in Westchester and you are welcome to come by hear it next time Im up there.

Regards
Dave

[dp951]

Cat gone

[grendiers]

If your car was intended for the European market, there should be no cat. I have a cat delete Euro exhaust in my garage with nothing to do. It's a bit beat up, but I'll check it out.

[CHICKS]

Originally Posted by grendiers

If your car was intended for the European market, there should be no cat. I have a cat delete Euro exhaust in my garage with nothing to do. It's a bit beat up, but I'll check it out.

I may be interested too. Include manifold? PM if you want to sell.

[smudo]

Originally Posted by philt68

i didn't realize this was going to turn into an in depth discussion of catalytic converters!..

leaving aside that controversial topic for a second, can anyone recommend a good exhaust solution-i'm not looking for it to sound like a formula one car, but at the moment, it sounds as though i'm driving a dyson vacuum cleaner (but slightly more exciting..)

One of the simplest solutions might be to replace the stock resonator with some free flow resonator, like Magnaflow etc. You will hear the engine more with open windows. However, that would require modifying of the original exhaust, thus if you would like to keep it, just replace the cat back section with custom or some aftermarket section with free flow muffler.

[grendiers]

Originally Posted by CHICKS

I may be interested too. Include manifold? PM if you want to sell.

BTW, this is for a 924 Turbo.

[dp951]

They are Parting out 924 turbo in miami

[emoore924]

I have a billy boat stainless cat-back on my turbo. Maint free. Reasonably quiet until you get on cam then it opens up nicely. Not sure if you can find them though and spensive if you do. Might be hen's teeth.

Will work with or without a cat, har.

[guru944]

Big congrats.
Will you bring it out to the PCA NY Metro grand concourse show in West bury, NY? We need more pics please. I would love to see it and meet you there...Pm me when you get a chance...
Later...

[Dave Colangelo]

The garage in this video looks quite familiar...

https://www.youtube.com/watch?v=cwwHULWCmkI&feature=youtu.be

Is that you?

If so I hope you come out to the thanksgiving gathering this year I would love to meet you.

Regards
Dave