catalytic converters

[cutt]

i'm thinking about removing them and installing simulators for th 02s.has anyone else done this?whats your opinions?not worried about breaking any laws just from a performance point of view is it worth it.how many horses would i possibly gain?

[DEFYANT]

not worried about breaking any laws just from a performance point of view is it worth it.how many horses would i possibly gain?
Horses? Not many. Today's cats are not very restrictive. And if you go with an aftermarket mid-pipe w/cats, the restriction is even less. Considering the fines and BS you'd go through for removing cats, you may want to rethink your plan.

Just my .02

[Rider90]

-POST DELETED-

[BillyGman]

I have mixed feelings about the thought of removing the cats. On one hand, I think they're very restrictive. have you ever looked inside a cat before? I have when I replaced my four stock ones with two magnaflow Hi-flow cats which came with the Kooks header and bolt-on exhaust package. And even the Hi-flow cats have a mesh screen on each side with very tiny holes that looked very restrictive to me. On the other hand, while I believe it's worth removing those original OEM cats that our Marauder come with, I'm not so sure that there would be anything more than perhaps a 15 HP gain at best with no cats at all as compared to having two Hi-flow cats like I've chosen.


But one thing is for certain, your car would definately be considerably louder w/out any cats at all. but i wouldn't remove cats just for louder sound since you can alwys go with those round straigh-thru design mufflers from Magnaflow, and that will give you plenty of noise even with the cats.

[David Morton]

Most people regret removing their catalytic convertors when they find out that that smell of unburned fuel stinking up their garage, the drive thru and anyplace else they have to stop and leave the engine running is a direct result of their 'great idea' to free up some horsepower.

Go round back behind your car now and take a deep breath through your nose. Smell anything offensive? You shouldn't. Now, remember that time you were sitting in a drive thru, waiting for your hamburgers behind a pickup truck or some other vehicle that had the nice bling all over but you had to smell that unburned fuel because he removed his cats? Were you aware you lost your appetite as a direct consequence of his actions?

Oh, it won't always run rich but it certainly will sometimes, probably a lot with this kind of car. I know I'm always hot-dogging it around town. If you do this selfish thing you're thinking about, you will be leaving a trail of that stink everywhere you go for other people to smell.

Besides, Defyant is 100% correct. Todays catalytic convertors are almost as free flowing as the pipe that you would replace them with. Only if you shipped the car to India and fueled it up with some leaded gas for a couple of tanks so they clogged up would you even notice a horsepower gain by removing them, which would just be gaining back the loss. Last time I saw a clogged cat was 1993 when you could still buy leaded gas. The fine for knowingly destroying or removing a cat (for pay) back then was $25,000. I am not aware of any changes to that law. The only exceptions were for off-road use or emergencies that were well defined.

And not only that but the engineers take into account the back pressure of the exhaust and make adjustments to camshaft timing and duration as well as fuel and ignition timing tables. Many times I've seen guys do what you're talking about and they lost bottom-end torque and driveability suffered.

Just don't do it!

[cutt]

if its worth 15hp its worth it to me.i can have an off-road pipe built for a good price and still retain my stock catpipe if i dont like it.

[FordNut]

if its worth 15hp its worth it to me.i can have an off-road pipe built for a good price and still retain my stock catpipe if i dont like it.
You won't get 15 horses, and will actually lose some low end torque.

[SergntMac]

The MM exhaust system was one of the first areas of discussion here 3 years ago, and it hasn't changed much. IMHO, following your plan to gain a few HP is probably not the best way to spend your money. Messing with the cats is a federal beef regardless of your state's local laws, don want to touch that. EPA dudes love seizing automobiles, every state DMV has a "gray market" law. Nonetheless, you can gain real (and legit) improvement by looking at your exhaust system as a whole.

The two most popular choices here, are the Kook's headers, or, the Cobra manifolds from Reinhart. Skip the discussion of header vs. manifold, and look at what both bolt up too? 2.5" OD exhaust pipe, high flow cats and X pipe, all pretty neat stuff responsible for as much as half the system gains over stock exhaust.

If you want to cut something off and get a real return on your investment, study these components for inspiration? I'm sure you will find a better (and legal) path to follow that fits your performance and budget needs. BTW, it will sound better too, and without a need to "simulate" O2 feedback, which could affect your future tuning possibilities.

I love exploring new ideas, but this ideal needs some discussion.

[maraudernkc]

The smell is nasty without at least a high flow cats.

We made 475RWHP on the stock cats.

Lidio, is making alot of RWHP on stock cats.

[RF Overlord]

^^^what Defyant, David Morton, FordNut, Mac, and maraudernkc said^^^

Aside from the fact that it's against federal law, you won't gain enough HP to be worth it, and the loss of TQ at the low end will DEFINITELY not be worth it...

[CRUZTAKER]

...... but i wouldn't remove cats just for louder sound since you can alwys go with those round straigh-thru design mufflers from Magnaflow, ......
I'm with Billy here.

I went with perforformance cats that have the 02 bung and actually deleted two of them.

I am still totally legal, yet have little resistance and more than enough sound.;)

[Warpath]

I've read that high flow cats vs. no cats is less than 10 hp improvement. But, I've never seen any data either way. I'm without cats and the smell isn't that obnoxious. I never eat in my Cobra either. I keep the garage open when its running. I never smell anything outside the car when driving even with the top down. That's beside the point. I think Bassani has some sort of metallic cat that is supposed to outflow even high flow cats. Get either high flow cats or the new metallic cats and have peace of mind.

[Glenn]

Ford Racing Cobra headers -#M-9430-E465 (ceramic coated) and Magaflow Cobra X-pipe w/hi-flow CATS (2) - #93335 will solve your problem. Note: X-pipe must be lengthened 4" to provide for the increased MM wheelbase. Good luck - they work great.

Glenn