CAT'* limit hp by a whole .1 from what I've heard long ago. You're not gonna gain much of anything if you run a straight pipe on a 3800, in fact you may lose torque.

Just keep it in if its a daily drivers, many cops will go ape if they find out you're CATless.

Yep, that is so true. And the only cars that see big gains, are the big block engines. 4, 6, and small block 8s don't see gains from removing the cat. And it isn't everyday you see a big block, daily driven. If you do, shake that guy'* hand.. because he'* gotta spend $30 just to drive 10 miles.

What happened was when emissions devices were released [widespread] in '72, they were pretty restrictive. They only had an EGR-Valve and a Catalytic Converter. Unfortunately a lot of the car companies hadn't really done the best job in the designs of the intakes then, and quite a bit of performance was lost. However I believe it was '74 when **** changed, and Pontiac did a great job on the design of that intake for their 400ci. High Performance Pontiac [HPP] did a test on the '71 intake [emission-control free], and the '74 and only saw a few HP difference. However, the cat was still a different story. They have sucked up until the last few years when they came out with the High Flow units. These won't make you lose power.

I completely understand when people say money is tight.. I know what that'* like. But if you don't have money, performance should take a back-burner. Keeping your car legal should be a little higher on the priority scale. And if you do, run without a cat.. at least keep it to yourself. You realize your name is all over your posts? And any moderator/administrator has access to your IP address, your name, general location, and usually significantly more information? They can give the EPA more than enough information to bust all those who publically admit to having removed an emissions-control device. Not to mention the nark gets money for it, too. Someone could easily make $1500 on the few people who have reportedily mentioned they don't have a cat.


-justin

Wow, Bill hasn't even jumped in on this one.

Boo.

Modifying a car isn't environmentally correct? I get 30mpg at 75 mph on the freeway, and my car runs clean with a good CAT.

Running without a CAT is illegal in all 50 States, can get you in alot of trouble, and I can get $250 cash for turning you in, as can anyone else that burns you.

Running WITHOUT A CAT is a HUGE polluter. As already stated above by Kyle, there'* really no performance benefit to deleting or gutting the cat, unless your car is a trailer-queen track runner.

I knew I was going to get hit! My comments were not pointed at anyone on here or anyone’* car . . . . . I never said that it is right or even anything close to that . . . . . . So take it how you wan't to (I really don't care), my only point was just find it funny that people will throw a huge cam, port there heads, run gobs of boost, and do other things that are just kicking emissions in the balls and then scream emissions because of a cat?

Cats are sized according to displacement, so saying that 4-6 cylinders or even a Small block engine won't see gains is just not true. The gains may not be big on a mild mod’d car but when you start hard core mods it’* a different story.

I've been to car shops, exhaust shops, tire shops - hell even dealerships multiple times and they haven't even questioned it. If you don't live in an emissions state no one cares!

EPA only cares about shops that will remove a cat. . . . . it is too hard to prosecute a single person because you not only have to prove they don't have a cat - you have to prove they removed the cat. Also you will only get the $$ if the defendant is proven guilty.

What about all the people the replace there cats with high flow ones? If I'm not mistaken it is against EPA laws to tamper with a cat unless it is damaged and then it has to be replaced by the dealer?

N E Ways!!!!!!

Sorry if my comments or the way I feel has affended anyone but Come On?!?! This has went from a comment about performance and people screaming emissions to people (including me) not having a cat. Jeez we are talking about not having a cat . . . . . . . .not a hit list with the president’* name on it? Do you honestly know how may people say things that they have done on forus (including this one) that are illigal? [cough] drinking . . . . . .speeding. . . . .the list goes on [/cough] Lets not act like we are in elementary school. I'm done with my rant. . . . .

Wow, talk about attention.....

Anywho, I didn't do this to my Jeep, and probably won't because I already have a high-flow cat on it. I am aware of the declining strength of the environment, but removing a cat isn't going to send it into overload and kill everybody. I was just pointing out that it is (what I thought to be) a neat trick to get some performance. Not a cool trick to destroy the o-zone layer. I do my best, when I can, to use as little gas as I can and not to waste it. I try to keep my RMPs below 2000 because of the insane gas prices and how much gas my rig goes through.

When I posted that, I wasn't thinking about ways to destroy the environment. I wasn't even thinking about the repercusions it would cause with emissions and what not. I don't want you all to think that I am an environment ****... "NO GOOD AIR FOR YOU!" So, I will appologize to the environmentalist... sorry.

Blazin, Cams, porting, and boost don't necessarily raise emissions, and if done right, don't make your car pollute more than it did stock. If your car is properly tuned, these mods don't cause more pollution. You may BURN more gas, but as long as you burn it properly (correct AFR), you're fine, and the catalytic converter will pick up what you miss.

No harm done, I'm just trying to clear up some misconceptions.

Not to add fuel to the cat or no cat fire, but I have tested the air flow to get real results. All flows conducted @ 20" of water flow depression (about 1.5" of Hg vacuum, the same as a 4-barrel carb is measured), the normal standard for exhaust measuring. The stock 1990 cat flows 223 cfm, gutted (completely empty) it flows 324 cfm, and equivalent length of straight 2.25" pipe flows 496 cfm. I need to get my hands on a "hi-flow" cat. to see what the real results are. No suggestions one way or the other, just data.