What was brought up by Barry is pretty much how I initially thought I'd word the original question before my idea snowballed and became some discombobulated person A vs person B hypothesis. Thanks for bringing that up, Barry.

And now, I bring myself back to hoping that the EPA gets back to me on my request for more info. As of now, the issue is a bit unclear. To explain how come I'm getting into all this, I'm talking to a person who'll remain anonymous, or Bob, who wants me to take out my catalytic converters because they're "not necessary" and "take away from the car'* performance."

I'd be more lenient toward Bob'* quotes, among other statements, if I were to own something other than 3 family sedans and a minivan. For crying out loud, the van is an Aerostar! It needs about 40 cats.

So, the second paragraph in this is the way I'd like to steer the thread, but I'd love to get in and out of talking about Barry'* comment. Thanks so much for the participation!

Before '80 or so, cars could still be non-catalyst from the factory if they could meet emission standards without it. My '78 Rabbit is factory non-catalyst. Any legal non-catalyst car will state "non-catalyst" on the federal emissions sticker.

As far as I know it is your responsibility when it comes to your cat.

Experience: I've taken my cars to a local shop for any cat work, and every cat I buy comes with a small slip that I must fill out and send in to the EPA confirming that my car has not has it'* cat changed in less than 50k miles. The shop that puts these cats on tells me to my face that I MUST turn in this slip and that it is not their problem if I "forget" to and the EPA is knocking at my door.

It'* not just the cats that can get you in trouble. Many of the mods discussed here on this forum violate Federal law. Plus there'* state laws stacked on top of that. California gets the most play due to their CARB laws, but Mass, NJ, NY are a few of the other states who'* emmisions laws stack on top of the federal laws.

Headers, cam changes, reprogramming the PCM/ECM, etc, etc, is violating Federal law (you are tampering with an emmissions control device on the car.) Though you rarely ever get caught doing it...half the folks enforcing the law would have no idea what they were looking at under the hood.

Ditching the cat in favor of a straight pipe is such a blatant abuse of the law that it gets caught. Including agents who troll the muffler shops looking to get somebody to put a straight pipe on a car...just to bust them.

I ran with no cat on the '87 Camaro for many years (actually, a falsey cat that was just a hollow shell) But, high flow cats are getting so good at passing exhaust gas that it'* foolish to hollow out a cat anymore.

On the other hand, if your car hasmore than 50,000 miles on the odometer, chances are that your cat has degraded enough that a new, high-quality high-flow will actually work more efficiently. In other words, most of the mild and medium modded cars here will meet or beat the sniffer test.

I thought headers (and exhaust mods in general) were legal as long as they did not disturb the factory cat from the factory position. Seeing how the exhaust manifolds on our cars do hot have an integrated cat (like the one on my old Hyundai did) headers ought to be legal, as I understand things, since they're not moving/deleting the cat.

Some States have more strict regulations.

Nope. Swapping headers is technically breaking the law. They are supposed to remain as the manufacturer installed. The exception is one that has an EOD tag from the CARB. While it'* a California thing, it is also a passes for federal as well (it'* a bit of a handshake agreement..if a company can get their product to pass CARB and get the EOD #, then it also passes DOT and EPA standards. Otherwise, the headers usually come with a sheetmetal tag on them "Off Highway Use Only. Not For Use On Pollution Controlled Vehicles"

Nobody really enforces this except as insult stacked on top if injury. You get busted for one item they were looking for, then start piling everything else on..."Oh, nice steel tube headers, that'* another violation on top of the cat, Ooops, where'* your Evap canister? Where'* the PCV valve? Missing an EGR valve are we?" Another violation, etc, etc. You get the picture. Only time I've ever heard of somebody getting busted for headers on their own was violating a county ordinace on noise pollution.

It'* getting crazier all the time...there are parts now that are illegal to sell in California PERIOD. Before it was just the usual "Not for sale and use on emmissions controlled vehicles" It'* one item that I constantly worry about....I'm building a car and really taking it on faith that in three years from now when it is done I'll be able to put a tag on it and actually drive it.

Bump! I haven't gotten any response whatsoever from the EPA. No one has replied to my contact attempt to answer my question about catalytic converter removal. What'* up? I figured it would be at least a little bit important to them to answer my question. Where could one go from here? Where do I go?

Considering all that has been written here, this is the shortest, most all-embracing post:

People don't go to court over it. They're fined. Period.