By Jason Bradley on Thursday, November 08, 2001 - 03:38 pm: Edit

For my 1990 Range rover I been goven a y pipe with the cats removed, the cat holders are still on but have been emptied. The O2 sensor plugs are clean and perfect to take new sensors( placed on the engine side of the cats on the rangie y-pipe) There are no emissions laws where I live. What would be the benefit of putting on this ypipe. I am changing my Tranny-oil and filter and am putting on new 02 sensors so I will be taking off the old pipe anyway. Pro's and Cons would be appreciated as I dont' know much about flowback etc and dont want to buy new cats if I don't need to... Thanks, JB

By PerroneFord on Thursday, November 08, 2001 - 04:01 pm: Edit

Assuming you don't live in the US, the removal of the cats provides marginal increase in exhaust flow which may give you 2-5 HP. Other than that, no real benefit.

By Dean Brown (Deanbrown3d) on Thursday, November 08, 2001 - 05:52 pm: Edit

You might piss off the guy behind you

By Dean Brown (Deanbrown3d) on Thursday, November 08, 2001 - 05:55 pm: Edit

5HP? from not having a cat? You mean I could double my power?

Just kidding?

Ps is this a dyno-tested fact?

By Robert Mann (Oldscout) on Thursday, November 08, 2001 - 05:56 pm: Edit

Spare the air! Keep them. I hate to sound like a treehugging greenie, but it makes no sense to remove them.

By ZPukajlo on Thursday, November 08, 2001 - 05:59 pm: Edit

Removing the cats won't make much difference in your power output. It'll just make your exhaust louder. On the plus side, it will be one thing that you won't have to worry about breaking while on a trail!
Perrone, there are some counties in the States that don't have emission laws. I live near one. Go figure!

Zane

By cartner on Thursday, November 08, 2001 - 06:20 pm: Edit

Sometimes, if your original cats are old and ready to move on, you can get a lot more than five hp. from taking those bad boys off....

By PerroneFord on Thursday, November 08, 2001 - 06:26 pm: Edit

There are NO states exempt from emissions laws. Certain states do not TEST emissions which is different. I live in one of them. This does not exempt me from penalty for removal.

Emissions are under Federal authotity, not state authority and tampering with emissions equipment is punishable in federal court, not state or local.

-P

By Dean Brown (Deanbrown3d) on Thursday, November 08, 2001 - 06:33 pm: Edit

Well if Mr Policeman climbs under, cuts open you cat and does a quick metals analysis, then you're gonna be in BIG trouble!

By JB on Thursday, November 08, 2001 - 06:42 pm: Edit

Oldscout - I don't buy the hype of Cat converters doing anything but sucking more gas and think it is the republican oil bastards like BUsh who make us use them to make us to burn just that teaspoon more of oil. Why do you think we are in Afganistan now?? www.alternet.org will give you real news.

As I am not a scientist I would like to hear from a greenie who has some facts on cats helping or hurting. anyone plz respond with links etc..

sorry - feeling anti-gov today cause we are dropping HUGE bombs indiscriminantly over there right now killing innocents - just to save Israels ass once again and protect the Kazak oil fields... Kind of like buying a rover to drive over 1 speed bump... sorry again Ill stop now..

By ZPukajlo on Thursday, November 08, 2001 - 08:10 pm: Edit

P-,

Maybe I worded it wrong. I never said anything about the States. Just that some Counties don't test for emissions. Anyway, in those counties you could remove the cats if you wanted to. I won't say you should or shouldn't, just that you could. Make sense?

Zane

By Robert Mann (Oldscout) on Thursday, November 08, 2001 - 08:45 pm: Edit

JB sounds like you missed High School chemistry and hung out in a Coffee shop in Berkeley.

Cats How they work :
In order to reduce emissions, modern car engines carefully control the amount of fuel they burn. They try to keep the air-to-fuel ratio very close to the stoichiometric point, which is the calculated ideal ratio of air to fuel. Theoretically, at this ratio, all of the fuel will be burned using all of the oxygen in the air. [For gasoline, the stoichiometric ratio is about 14.7:1, meaning that for each pound of gasoline, 14.7 pounds of air will be burned. The fuel mixture actually varies from the ideal ratio quite a bit during driving. Sometimes the mixture can be lean (an air-to-fuel ratio higher than 14.7), and other times the mixture can be rich (an air-to-fuel ratio lower than 14.7).]
The main emissions of a car engine are:

Nitrogen gas (N2) - air is 78 percent nitrogen gas, and most of this passes right through the car engine.
Carbon Dioxide (CO2) - this is one product of combustion. The carbon in the fuel bonds with the oxygen in the air.
Water vapor (H2O) - this is another product of combustion. The hydrogen in the fuel bonds with the oxygen in the air.
These emissions are mostly benign (although carbon dioxide emissions are believed to contribute to global warming). But because the combustion process is never perfect, some smaller amounts of more harmful emissions are also produced in car engines:
Carbon monoxide (CO) - a poisonous gas that is colorless and odorless.
Hydrocarbons or volatile organic compounds (VOCs) - produced mostly from unburned fuel that evaporates. Sunlight breaks these down to form oxidants, which react with oxides of nitrogen to cause ground level ozone (O3), a major component of smog.
Oxides of nitrogen (NO and NO2, together called NOx) - contributes to smog and acid rain, and also causes irritation to human mucus membranes.
These are the three main regulated emissions, and also the ones that catalytic converters are designed to reduce.
Most modern cars are equipped with three-way catalytic converters. "Three-way" refers to the three regulated emissions it helps to reduce -- carbon monoxide, VOCs and NOx molecules. The converter uses two different types of catalysts, a reduction catalyst and an oxidization catalyst. Both types consist of a ceramic structure coated with a metal catalyst, usually platinum, rhodium and/or palladium. The idea is to create a structure that exposes the maximum surface area of catalyst to the exhaust stream, while also minimizing the amount of catalyst required (they are very expensive).



There are two main types of structures used in catalytic converters -- honeycomb and ceramic beads. Most cars today use a honeycomb structure.



Photo of a ceramic honeycomb catalyst structure.


The Reduction Catalyst
The reduction catalyst is the first stage of the catalytic converter. It uses platinum and rhodium to help reduce the NOx emissions. When an NO or NO2 molecule contacts the catalyst, the catalyst rips the nitrogen atom out of the molecule and holds on to it, freeing the oxygen in the form of O2. The nitrogen atoms bond with other nitrogen atoms that are also stuck to the catalyst, forming N2. For example:


2NO => N2 + O2 or 2NO2 => N2 + 2O2
The Oxidization Catalyst
The oxidation catalyst is the second stage of the catalytic converter. It reduces the unburned hydrocarbons and carbon monoxide by burning (oxidizing) them over a platinum and palladium catalyst. This catalyst aids the reaction of the CO and hydrocarbons with the remaining oxygen in the exhaust gas. For example:


2CO + O2 => 2CO2
But where did this oxygen come from?

The Control System
The third stage is a control system that monitors the exhaust stream, and uses this information to control the fuel injection system. There is an oxygen sensor mounted upstream of the catalytic converter, meaning it is closer to the engine than the converter. This sensor tells the engine computer how much oxygen is in the exhaust. The engine computer can increase or decrease the amount of oxygen in the exhaust by adjusting the air to fuel ratio. This control scheme allows the engine computer to make sure that the engine is running at close to the stoichiometric point, and also to make sure that there is enough oxygen in the exhaust to allow the oxidization catalyst to burn the unburned hydrocarbons and CO.

NOT MY WORK, JUST a CUT AND PASTE.

By Craig on Thursday, November 08, 2001 - 08:49 pm: Edit

Jason-
I ran the same setup on my 91RR for a while and found that the O2 sensors will provide incorrect resistance without the heat that the converters supply. Thus providing incorrect fuel mixture which leads to fouled O2 sensors. I learned the expensive way, keep the cats in place.
Craig

By Phillip Perkinson (R0ver4x4) on Thursday, November 08, 2001 - 08:49 pm: Edit

can you get headers for rovers on this side of the ocean

By PerroneFord on Thursday, November 08, 2001 - 09:38 pm: Edit

ZP, makes perfect sense. The whole state of Florida doesnt' test for emissions. Most people still run cats though. People here are pretty uptight about enviro issues, so most don't take the risk. If you can get away with it, and you wan to, open up your exahust!

-P

By Kyle Beckman (Kbeckman) on Thursday, November 08, 2001 - 09:40 pm: Edit

Oldscout,

You just caused me to have bad flashbacks from college chemistry!

By Robert Mann (Oldscout) on Thursday, November 08, 2001 - 09:51 pm: Edit

Good to hear that Kyle! now see if you can figure out what my e-mail address means.

By ZPukajlo on Thursday, November 08, 2001 - 10:17 pm: Edit

You would think they would test for emissions if the public is uptight about the issues. To each their own. Personally, I would like to see road worthy test's along with emission test's. We could get a lot of vehicles off the road. But that is another subject.

Zane

By Dean Brown (Deanbrown3d) on Thursday, November 08, 2001 - 10:27 pm: Edit

Sodium hydroxide

By Robert Mann (Oldscout) on Thursday, November 08, 2001 - 10:56 pm: Edit

Close Dean it's Caustic Bob

By Dean Brown (Deanbrown3d) on Friday, November 09, 2001 - 08:02 am: Edit

Makes sense - rather than SodiumHydroxideBob!
But you don't seem so caustic

By Dean Brown (Deanbrown3d) on Friday, November 09, 2001 - 08:05 am: Edit

Ps keep away from H2SO4Amy

By Bill Bettridge (Billb) on Friday, November 09, 2001 - 08:36 am: Edit

JB

Dropping bombs indiscriminately to save Israel's ass!? - WTF

Innocents - yeah we got about 6000 of those innocents dead here.......

Did you also forget 9/11/01 as well as chemistry?

By Ron on Friday, November 09, 2001 - 08:59 am: Edit

Cut them out.

Craig,
Are you sure? What is the difference between the Euro spec non cat trucks Eprom and the US spec ones? I am hard pressed to believe that the O2 sensors need heat from the catalysts.

Ron

PS Your average late 80s RR will PASS emmissions without cats.

By Dean Brown (Deanbrown3d) on Friday, November 09, 2001 - 09:54 am: Edit

Bill and Jb please take this argument to another thread.

Right - lets get back to chemistry....

English chem joke: What does a policeman earn on the late shift?


Answer: copper nitrate

By E Snyder on Friday, November 09, 2001 - 09:59 am: Edit

JB-
If you think we're just over there to save Israel and protect oil fields, you obviously didn't know anyone that died in NYC, and you must live in an area that has no possible threat of a terrorist attack. Are you oblivious to the fact that Bin Laden and his cronies have made it their sworn duty to kill US citizens and are actively looking for nuclear weapons to use against us? It's the only way I can even imagine coming up with that point of view right now. Unless you're an Arab. Then that perspective might at least come genuinely, even if mistakenly.

By Robert Mann (Oldscout) on Friday, November 09, 2001 - 10:08 am: Edit

Come on Dean a Exothermic Reaction with Amy sounds like fun!
Hook me up1
H2so4 is 10.62 lbs/gallon what size is she?

By Craig on Friday, November 09, 2001 - 07:58 pm: Edit

Ron-
I know absolutely nothing about the euro spec rigs, but I think Oldscout hit it on the head.
Mine passed the etest when they were hollow, and it took a good 6 months for the sensors to foul. Also, the open cats take away some bottom end, but overall the it seemed to rev a little quicker. Open or stock, the exhaust will only flow as much as the dinky factory exhaust manifolds. All this exhaust mod business is fruitless unless the manifolds are hogged out or a set of headers go in their place.
Craig

By cartner on Saturday, November 10, 2001 - 11:19 pm: Edit

Innocents...wow...tune in Tokyo...HELLO! where is your head? wait, I think I know....

By JB on Sunday, November 11, 2001 - 02:22 pm: Edit

Oldscout - I am doing my exhaust homework after getting my feet wet with this cat thread, thanks for the great lesson. I am reconsidering \Summit Racing cats but will look into the temp issue running without cats.
We had a great weekend running up Lower #2 and down Lower #2 in Tellico, N.C. ( 2 D-90s , 35 inch SWB Rangie and a LWB Rangie - yes LWB up lower #2!)
The trails were dry and very few other trucks out and almost no 4 wheelers or bikes.

I feel the US offers too much financial and political support to Israel and this is the main reason Bin Ladin and his and numerous other Muslims hate us. Just my opinion though.

By mike w on Sunday, November 11, 2001 - 04:33 pm: Edit

as a note...... the US had ear marked several MILLIONS of dollars to aid the Afgans. oh this was before the trade center murders! so it isnt a matter of econmics. as far as offering any support, we help all those who ask. it really doesnt matter if we supported the Israelies or not, we are the big man on the block and every piece of shit, wanna be hero, is always wanting to take a stab at the championship. its not Israels fault that the two jets were rammed into the trade centers, its ole Bin's. Bin's belief is that if you are not a Muslim then you must die. plain and simple make the world Muslim that is his political goal, his war. as did the english did several hundred years ago he now is attempting to do the same but in a more twisted manor. express your opinion JB even if it is wrong.

By JB on Sunday, November 11, 2001 - 07:29 pm: Edit

http://www.sepp.org/controv/catalytic.html

Oldscout, here is a cut and paste retort to your cut and paste. Mine explains why Catalytic Converters are bad - it was only 4 clicks away from the same Google search you did! Thanks UC Berkeley & Starbucks and my HUGE trust fund to allow me the time to search out the truth, Like Deng Xiao Ping says, " seek truth from fact" ;p

Mike W - billions in arms, trade and political support for Israel Vs. a few million to stop a large percentage of the Afghani Poppy cultivation. It does "really matter" . We are not an impartial Big Man which is why we are despised by certain Muslims, not for being capitalists. Hopefully the new Palestinean State will resolve the issue of Palestine and Israel, We need also to selectively kill the Taliban and not the innocent ignorant woman and kids who will be starving and freezing tonight as we bomb them for doing nothing but living in the wrong place as I type this. It's not" if you're not Muslim you die" read the Koran, Islam is Very tolerant, Osama of the Pashtun is not! Don't stereotype Muslims.

By Robert Mann (Oldscout) on Sunday, November 11, 2001 - 07:59 pm: Edit

JB did you read all of it? The last lines are:

NOTE: The New York Times reporter's statement that nitrous oxides now comprise 7.2 percent of the gases that cause global warming appears to be wrong. If N2O is 7.2 percent of the greenhouse gases, and it's 300 times more potent than CO2, that would make it the primary greenhouse gas. The primary greenhouse gas is water vapor. Either the EPA has omitted water vapor altogether in its calculations, which would be very wrong, or the reporter misread the report and what the EPA actually meant was that N2O accounts for 7.2 percent of a putative warming effect. Quite different. The N2O figure should not be cited until verified.

By mike w on Sunday, November 11, 2001 - 08:24 pm: Edit

lol....i spent 45 mins typing a "PC" response but screw it! nuke em til they glow!

By JB on Sunday, November 11, 2001 - 10:01 pm: Edit

I agree with a calculated death blow Mike, but let's just make sure we are killing those that need it and not just creating the next generation of orphaned suicide bombers, oh wait we could kill them too and their friends, hell lets just kill everybody that isn't on DiscoWeb , that should make enough of "them/'em" to satisy your desire for blood. It is an us and them world is it?
I erase 98% of what I type and the %2 that makes it sure ain't the best by any stretch but it beats your American Joe Shithead response of screw em nuke em. You are but a sheep in a huge flock of dumb f*** other sheep. And if it takes 45 minutes to type a simple thought you are really hurting in the brains dept. You must be one big dumb red blooded motherfucker ;P Try stream of consciousness where you just let it out, screw PC!

By AMERICAN JOE SHITHEAD on Monday, November 12, 2001 - 08:32 pm: Edit

JB are you in afgan? what is it that you would have us (oh i mean American Joe Shithead) do? let this go. you cant have a war without people dying. i would have thought that someone as intelligent as you would understand that. its a terrible thing that those who cannot control their destiny have to suffer for the sakes of someone elses religous beliefs. its even sadder that the leaders of these people put the innocent in harms way. there is now and has always been a simple cure......surrender Bin Ladin. it is apparent that you are not or choose not to be a member of the United States. take a moment and think about what you are typing and what is it you are trying to tell us, and all that name calling, common JB if you want to piss me off make fun of my dog. calling me names will not change my political views it only strengthens my desire to punch you in your nose. if you want to compare brain pans find someone else to impress, if you want to make this personal, i never run my email is posted, i can give you my address and we can settle this the midwest way. if you want we can sit share a bottle of sambuca and a fine cuban cigar by my fire and discover each others softer side by crying over mans cruelity to man or we can just run out back behind the barn and fight it out. i perfer the sambuca. the nuke em til they glow response comes from knowing people that are still buried in the rubble of the towers. i really dont think that nuclear weapons are the solution to the problems we face. its just one American Joe Shithead expressing his discontent with what one scumbag placed on his plate. it does not in any way reflect that of the owners and members of the Discoweb. its mine and mine alone. if you are offended, then let me extend the olive branch and offer you a humble apology! it is sincere. i have met many many intellgent people in my 41 years and have met these people in places like Egypt, Serria Leone, too many South American countrys to list and even in here in the United States. i have met many people who would argue with the dawn in an attempt to make the moon rise. the one thing i found that all of these great minds combined with all the "simple" thinking ones that they all have one thing in common....like their assholes their opinon stinks.
oh would you want to trade your steel wheel spare for one of my alloys Castors.

By JB on Tuesday, November 13, 2001 - 01:31 pm: Edit

Well put Joe - sambuca and cigars are much preferred to knuckle busting. I grin now that I see I wanted to fight old Mike W for not being enough of a pacifist. After wrestling with a few CVs and U joints I have calmed down and see the paradoxical aspects of my rant. This is a great board and I enjoy being able to read everyone's opinion, ripe or not, and I appreciate you holding your nose when I let mine loose. If that's a Romeo Y Julietta cigar I'll meet you in 2 weeks at Tellico, trail #2, the rock garden. Bring some spares JB

By mike w on Tuesday, November 13, 2001 - 01:37 pm: Edit

if i can be there i will, if not i will save them til we meet. peace be with you....