I'd be interested in a photo DIY also but in the meantime...

As I understand it, there are two flaps in the air intake circuit, one near the EGR valve and another in the intake manifold (underneath, where it's hard to see, much less touch). These flaps get gunked up with exhaust that the EGR valve lets in when the engine is cold. Eventually they gunk up to where they stop working properly. The purpose of the flaps is to "tune" the intake pipe so that it resonates properly for any given engine speed -- it's similar to tuning a speaker system with ducted ports and such. The tuning is one of the reasons why the 606 NA engine makes almost as many ponies as the older 603 turbo engine.

All you have to do is to take the intake plumbing apart, clean all of the gunk off of the inside (including the flaps) and put it back together.

It should also be possible to temporarily defeat the function of the EGR valve for testing purposes only by putting a piece of sheet metal at the place where the EGR valve mounts onto the intake ducting. The electronic and vacuum components will continue to function normally so the computers won't throw any codes but the dirty exhaust gases will be kept out of the intake. Once you have confirmed that the intake is now staying clean, you can restore the EGR valve to functionality by removing the block.

I intend to try this myself but have not yet so I cannot vouch for its effectiveness. Others have disconnected and plugged the port in the exhaust system and connected the EGR valve to a small filter. Thus, air is still allowed into the intake but it is now clean air instead of dirty exhaust. Note that this latter trick may not work on the later turbocharged engines.

Jeremy

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"Buster" in the '95

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