whats the airpump in the fender actually do?

 

It's an emissions device that, if I am wrong you can correct me, pulls air around the intake manifold, the valve device on the back, around to the larger connection on the intake pipe. How this reduces emissions I don't know, sorry if that was your main question.

I think this is mostly used by your stock computer when at a stop or that's when I heard mine kick on most of the time.

 

So when I put my aem ems in I wont need correct?

 

It pumps air into the exhaust. When the exhaust valve opens there are unburned hydrocarbons exiting the exhaust at a high temperature. The reason that they are unburned is there is no air/oxygen left to complete the burn.

If you add air to the high temperature unburned hydrocarbons they will continue to burn and further reduce the hydrocarbons entering the catalytic convertor, thereby reducing exhaust emissions.

This type of system has been in place since the 60's, long before catalytic convertors were in use.

As manufacturers improve combustion chamber shapes, etc. the need for the air pump is reduced.

 

Greenlight, how does this pick up unburnt exhaust gasses when one valve is attached to the intake manifold and the other to the intake pipe?

Correct GDM S2k when you get the AEM EMS, like me you won't need this system any longer. After another thread I put up here I found out that with all the piping removed you do not need to block off the valve if it is left in place. The valve only opens when a pressure signal is seen.

 

There is an exhaust "crossover" (actually it's an AIR (air injector reactor) crossover) in the back of the cylinder head. The air that you think is entering the intake manifold is actually crossing over in the rear of the cylinder head and is going over to the exhaust side of the cylinder head. There is a long thin stainless steel cover just above the exhaust header on the cylinder head. If you remove that cover you can see the crossover near the back of the head (approx. a 1/2" hole). You will also see four holes (approx. 3/16") under the cover that direct the air into the exhaust ports near the backside of the exhaust valve. Some other car manufacturers use tubes that attach to the exhaust manifold, but Honda wisely choose to use a passage in the cylinder head and injector fresh air right behind the exhaust valve where the unburned gases are the hottest.