hey guys,
I have heard about people removing the smog pumps for various reasons. What does this do. Does it have anything to do with the converters. Because I am about ready to remove mine.(can't afford to replace.) And also, by removing the converters. Will this cause any damage to my truck. I will still have mufflers.

thanks
Matt

 

should cause no damage, the only time it may cause some grief is when inspection time rolls around.

 

when I put headers on my 95 460, The exhaust place put caps on my new catalatic converters when I got a new exhaust and I removed all the smog pump componants. My only problem now is now that the pump is gone, when I replace the belts I have to have a measurement, I did this by running a string where the belt goes and measured how long it was, and get a different belt. Of course if you still have the manifolds you will have to rig some kind of caps where your smog pump connects to your manifolds, but i have not done this and I dont know if that will work. To conclude the smog pump system is not needed, and it will not hurt to remove it

 

You should also remove the cat, The cat needs air from the pump to complete the burning of unburnt fuel. The cats may become pluged if they get no air.

 

Cats are designed to convert exhaust gases into other gases more environmentally friendly, they are not intended to burn off unburnt fuel. That's how catalytic converters go bad, they have raw gas going through them and they over heat and break apart or melt. If you take away the source of air injection, one of the chemical reactions won't take place as it would if there were oxygen present, so one of the exhaust gases might be present at a higher concentration in the exhaust.

 

The cats will build up carbon if no O2 is present, It doesnt take much to plug up a cat. Ever wonder why there is air injected into the cat? The cats will not get hot enough to burn stuff off like carbon and motor oil.

 

The cats build up carbon and other residue because of unburnt fuel, etc. in the exhaust. If O2 injection is manditory for this to happen, why is it that not all vehicles have these 3 way oxidation cats? What about the first cat on our Fords? It doesn't have air injected to it all the time; it gets some air from the injection into the heads just after start up, but after the truck warms up, air is diverted to the injection before the second cat, and sometimes, air is just dumped back into the air and not injected to either place.

"Fuel, oil and antifreeze cause a different type of brick destruction. Under normal operating conditions, the catalytic process doesn’t begin until temperatures inside a converter reach 500 to 600 degrees (F). If air/fuel ratio is on target, and the exhaust is free of contaminants, internal converter temperature stays at about 1200 degrees. But when unburned fuel enters the picture, temperatures can reach 2200 degrees and either burn the precious metals out of the washcoat, or literally cause a melt down of the bricks. Extremely high temperatures can also result in destruction of the mat that's wedged between the bricks to the converter case.

"Oil and antifreeze also cause elevated temperatures, but as the converter tries to burn (oxidize) these compounds, a residue, which plugs up the bricks is formed. At this point, the converter not only looses its effectiveness, it also becomes very restrictive to exhaust flow, which kills horsepower."
from http://www.randomtechnology.com/technical.html read it yourself

If a converter is forced to burn off contaminants in the exhaust, it will be ruined. So if the cat is messed up already, that means that there is some problem with the tune of the engine, and that must be corrected before a new converter can be put on, because the new one will be destroyed just as quickly as the old one if it has oil and unburnt fuel going through it. The air injection into the cat has nothing to do with burning anything off, it's there to aid in the reduction of harmful gaseous emissions in the exaust.

mstaser, the stuff you want to do should cause no harm to your truck, although it will have a hard time passing inspection if you have emissions inspections in your area.

 

Isnt it illegal to have no Cats on your truck unless its 1976 or older?

 

thanks everyone for the help. I have already ripped out the innerds on my cats. And in a week or two I will be taking them out all together. We do not have any inspections on vehicles in my area YET. and it is illegal to take the cats off. But the cops don't care about that around here unless your exhaust is just screamin loud. I guess I will just take all that smog junk out just mainly to get it out of the way.

thanks again.

 

The specific purpose of the catalytic converters is to burn unburnt fuel - that's why they need an air supply to work. Newer cats also handle NOx & CO, but they all handle unburnt fuel.

 

So why do none of the new vehicles have smog pumps or air injection for their cats? Cats aren't designed to burn off anything, it's burning stuff that destroys them. That's why federal law says that if a catalytic converter fails, the cause must be identified and corrected before a new one can be put on. Most of the time it is because of contaminants, either fuel, oil or antifreeze going through the cat and super heating it, melting it, and plugging it up. The converter does exactly that - it converts molecules of the air to other molecules that don't harm the environment so much. It's not an afterburner, it's a converter. And if you guys get a chance, that web page I linked to in an earlier post is a good place to read and understand what catalytic converters do.

 

The Catalytic converter will only over heat if there is an overly rich condition. The ECC controls this by not dumping air into the cat at cold start up, or open loop situations and extended idle. During normal operation an oxygen-rich enviroment is needed to maintain the heated chemical reaction needed for oxidation of polutants.

 

Exactly...i.e. if it's trying to burn off any unburned fuel or oil that's in the exhaust. If the engine is properly tuned, there should be very very minimal amounts of unburned fuel in the exaust anyway. If it's working properly, there will not be a big build up of carbon in the cat, because it's changing gas molecules, not trying to burn anything.