# air induction valve bypass



## scout (Aug 24, 2007)

trying to get my 89 d21 ready for the engine install. Took a look today at the air induction valve assembly. Of course it is corroded so much as to be totally useless as a holder for the filter. Did a search on that subject and it seems all it does is provide air into the exhaust manifold for pollution control assistance. It looks like the flow is regulated to some extent just by the amout of plumbing that is hooked up to it. Seems to me that all I am missing is the case the filter fits into and the vaccum line on the back senses it there is flow to the system. There are no valves on the unit. Would it be possible to just provide the output line with an unobstructed flow of fresh air and not have to replace the cannister that holds the filter? Am I missing some other function that would preclude this type of arrangement? None of the searched threads mentions any penalty for the system not being assembled correctly. 
Anybody got any good ideas besides buying a replacement cannister and filter?


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## SPEEDO (Jun 9, 2003)

if I remember, there are some reed valves in there....


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## scout (Aug 24, 2007)

Are they to prevent backflow from the exhaust manifold or to regulate flow to the exhaust manifold. Mine is so corroded it is difficult to tell exactly what used to be in there.
Thanks for the info.


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## Keone777 (Sep 24, 2008)

Bump. 

I'm looking to take off my exhaust manifold, but the metal tube running from the Air Induction Valve down to below the manifold is blocking the way to remove the heat shield. The bolt holding it to the exhaust is rusted, stripped and stuck.

Can I just remove it and put a straight pipe on later?


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## scout (Aug 24, 2007)

Keone777 said:


> Bump.
> 
> I'm looking to take off my exhaust manifold, but the metal tube running from the Air Induction Valve down to below the manifold is blocking the way to remove the heat shield. The bolt holding it to the exhaust is rusted, stripped and stuck.
> 
> Can I just remove it and put a straight pipe on later?


I think that would work fine. If I remeber correctly all I had left was a piece of metal pipe with a piece of rubber hose stuck on the end. Straight pipe should work fine. Good luck


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