They say that the AIR pump helps the catalytic converter to break down CO1, and I'm sure it does to some extent; but not nearly as much as they claim.
Lets suppose that you take a glass with 9 ounces of water & add 1 ounce of alcohol. The alcohol level is now 10%. OK, you pump in 10 more ounces of water; now the alcohol level is 5%. You haven't reduced the amount of alcohol one #*@!! bit -
You sample some exhaust fumes, and it shows X % of CO1. OK, you hook up an air pump and pump in a bunch more clean air, the percent of CO1 goes down, BUT MOSTLY YOU'VE JUST ADDED MORE AIR!
Like I say, I'm sure that it does help the cat to work but not to the extent that they claim. Mostly its just a numbers game to fool the government. - and of course they, are not very bright. (Bill-S.1766)

OK, so what do you pay in energy to run this little jewel? Well, there is the drag on the engine to turn the thing. There is all the vacuum that's taken away from the intake to run all the vacuum switches and gismos(and screwing-up ur fuel/air mix). There is the electrical ECM connections to keep it in line. There is all the extra back pressure in the exhaust, caused by pumping in more air. ALL, making your engine work harder. AND WHEN AN ENGINE WORKS HARDER IT BURNS MORE FUEL & MAKES MORE CO1 !!

 

is this an april fools joke?

 

A very poor understanding of chemistry to say the least...

What's actually happening is that the job of the cat is to turn carbon monoxide into carbon dioxide. But since you can't turn carbon monoxide into carbon dioxide without some oxygen, the AIR pump supplies a smal amount of clean air so that the cat can do its work. Its job is not to dilute the exhaust with air; it takes very much less air than exhaust to make it happen.

No matter what "they" "claim", just hook a car up to a sniffer sometime, and measure the CO content of the exhaust with and without the AIR operating. You'll find that regardless of what "they" "claim", it makes a significant difference to emissions.

It takes less than ½ HP to work the system. The amount of back pressure it adds is negligible. The overall effect on an engines power output, efficiency, etc. is basically unmeasurable.

 

The catalytic converter is a honeycomb of platinum dust(sometimes other things) that catalyzes reactions between hydrocarbons and carbon monoxide into carbon dioxide and water.

The net chemical reactions involving oxygen are like this:
C2H4 + 3O2 ------> 2CO2 + 2H2O
2CO + O2 ------> 2CO2

You see that oxygen(O2) is a reactant, and adding a reactant drives the reaction forward, thus reducing the amount of carbon monoxide(CO) and unburned gas(C2H4).

 

All the above items (C2H4, CO, CO2, O2) are reactants. CO2 and H2O are the products.... Man, I'm dusting off 10 year old Chemistry in my head.

Oxygen is the oxidizer, and the Carbon in both CO and C2H4 is the reducer.

 

Glad you posted that; I always thought the same thing. I figured they might as well hang the sniffer outside the tailpipe, nearby, instead of inside. Seemed like the same thing to me.

Does the AIR system shut off the O2 supply to the catalytic after a certain period, too? Think adding an AIR pump to an F-body that never came with one would help the car pass emissions?

 

The air is pumped through the exhaust manifolds until the car enters closed loop, then it is supplied to the catalytic converter as long as the engine is running. Adding an air pump to a car that never had one will reduce emissions if it has a catalytic converter, otherwise it would just be like the first post said.

 

I actually did just that about 6 years ago, and my car ran cleaner with the AIR disconnected than it did with it connected. Not much, but slightly. Both HC and CO dropped slightly. Not what you wanted to see I'm sure.

 

There has to be some kind of explanation for that, max. Science shows that should not happen. Perhaps an old/partially clogged catalytic converter could be to blame. You really need to run many many tests to confirm exactly how effective the air system is.

 

I know the reason a lot of people get rid of it is to just get the huge piece of crap out of the way, and to save some weight. Would it be possible to rig up some sort of small electrical air pump that would get the job done, as well as reducing engine compartment clutter?

 

The smog pump makes a great, built-in, blower to keep the back drum brakes clean and possibly cooler. I have a tube that runs straight from the pump to a T-fitting in front of the rear axle and then tubing through the brake-adjuster holes. 10,000 miles later, my drums had barely ANY dust and the drums are probably kept much cooler from the constant airflow inside the drum.

 

Well it was actually a fairly new converter on the car. When I took it in, the AIR was disconnected like it always is, at the time just the belt was gone. So we stuck the sniffer in the pipe and the HC was a little too high. He said maybe we should hook up the air pump, that will help. So we hook it up and both watched the HC and CO climb. Didnt make much sense to either of us, but thats what it did. I took it out for a drive, didnt help. Pulled the belt, it dropped again. Messed with the timing a little and got it to pass. Another car I have here has never had the AIR installed on it and it passed smog with flying colors with just a cat. It actually met standards for a 99 car. I have little faith in the AIR system.

 

I think there is one variable that is being overlooked in the equation. Temperature of exhaust gasses. You can't tell me that a catalytic convertor with exhaust gases inside it magically transforms Carbon Monoxide into Carbon Dioxide and water. You need to remember that the temperature of the exhaust dictates the catalytic effect. If the exhaust is too cold the catalyst won't work. If your headers are glowing redhot I am sure your exhaust gasses would be almost breathable heh..