Catalytic converters... replace or remove...?

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La rabona

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my cats are no good and i removed them,i have a magnaflow muffler btw any advantage or disvantage by removing them?
 

SunlitComet

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1. illegal in any state.(I don't care about anybody else here saying it is.) 2. warning light and associated codes for malfunctioning emissions equipment. 3. likely running in occasionally resulting in more fuel use. 4. bad for the environment. 5. affects performance. and 6. ...

IT IS ILLEGAL IN ANY STATE TO DO SO BY FEDERAL LAW.
 

soulsea

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Yes it is illegal to run without one in any state, and yes it will likely throw codes ... as to the other stuff, unlikely.

If you drive an American automobile of a later year than 1975, which should be about everyone in America, it has a catalytic converter. Unless it's older than 1984 in which case you can cut the sucker off, and pitch it. The catalytic converter or "cat" for short was first thought of in the early 1950s by a french engineer living in L.A. named Eugene Houdry. He was tired of all the smog, and worked in catalytic oil refining. The first production cats weren't introduced until 1973 when lead was taken out of gasoline as an anti-knock agent, and some other guys fussed around with the design, and improved it. Lead gunked up the converter. By 1975 all vehicles had to have a cat from the factory, and by 1985 it was a crime to take it off your vehicle if it was built in that year, or later.

The idea behind the cat is to burn unburned hydrocarbons(fuel molecules) left over from the combustion cycle. It wasn't really too bad of an idea for the time because cars were carbureted then, and the fuel mix ratio was just set to the best compromise for most conditions. If it got cold, or you had a big drop in altitude it would be a little lean, if it got hot, or you went up into the mountains it would be a little rich. Most of them were set on the rich side because a spark ignition engine runs better a little rich than it does too lean. So this meant unburned fuel coming out the tail pipe. The cat was supposed to burn this extra gas and clean up the emissions. Good idea right?

Maybe sort of at first. The biggest problem with early converters is that they took a long time to get hot, and they had a problem staying hot enough to burn the fuel all the time because the carburetor wasn't always that far off, and sometimes was too lean to keep the cat hot, but rich enough to still waste some gas. Enter the smog pump. It blew air into the cat like a blast on a furnace to keep it hot, and the carburetors were intentionally set even richer to make sure they wasted enough fuel to keep the cat hot. Plus the smog pump pulled about 5 horsepower. So now we are wasting fuel to support a device to catch wasted fuel, brilliant. Now I'm sure all the oil companies were just heart broken that every single car on the road was going to have to consume about 30% more fuel to catch any incidental unburned fuel that might escape due to the carburetion system.

Then in the mid 80s we started getting good at fuel injection, and now we can control how much fuel the engine gets at any time. Coincidentally about the same time the feds mandate the catalytic converter to be on all engines about 25HP all the time, for all time, and with no exceptions, EVER. A little convenient? Seeing as there should be very little waste fuel now that we can accurately meter the fuel to the engine's needs. Your modern vehicle's computer is now so sophisticated that it can vary the pulse of every injector by 1/100th of a gram every single rotation of the engine. There is absolutely NO reason whatsoever for a modern vehicle to have a catalytic converter. Accept that it takes about 15%-20% more of your fuel(read money) to keep it hot, and running. Better than the 30% or more from days of yore, but still very wasteful. Not to mention the less than beneficial side effects produced by the cat. Like acid rain from hydrogen sulfide.

Anyone with a moderate understanding of combustion theory, and an understanding of engine control systems knows that a properly electronically tuned engine burns many times cleaner than the federally mandated system. Some european contries won't even allow california smog equipped vehicles in their country because they are so dirty. At our current level of technology it is abundantly apparent that it has nothing to do with clean air, and everything to do with $$$.
http://www.abovetopsecret.com/forum/thread572015/pg1
 

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