Hey, anybody have any information on the EAI CONTROL VALVE for an SR20DET.

  • What is it’s function?
  • It is required?
  • Why does HKS make a product called the “HKS SILVIA SR20DET EAI CONTROL VALVE TRANSFER KIT RPS13/PS13”

Reason being is on occassion my car will hunt for an idle. When it does that the EAI circuit opens (as viewd on the PFC Commander). I need to find out more about the EAI Valve.

In all of hte documentation I have found on the web people seem to think it has to do with the EGR stuff - but no 100% confirmation.

Any info would be great.

This is what my understanding of it is Dan.

EAI (Exhaust Air Intake (valve))

What it does is let clean air into the exhaust system, I can’t remeber if this is via the intake pcv pipe or not its been a while since I’ve looked at one because I ripped mine out when I put the SR in. The reason it does this is to quickly warm up the CAT so it can start doing its job quicker. The air is let into the exhaust via the downpipe right in front of the CAT.

I notice my car also lights up the EAI circut on occasion but it doesn’t seem to affect my idle. The valve is controled via engine vaccum and is not required.

As for the HKS product… I have no idea.

Again this is just what I have gathered from seeing the EAI and playing with my PFC. I may be completly talking out my ass. :slight_smile:

But I think I’m right… of course I usually do.

Thanks D - You said you ripped yours out. Where “was” it?

i highly doubt you still have that system in place, its basically the egr valve that everyone takes out that connects to the turbo extension from my understanding.

It was bolted to the inner driver side fender… right below the power steering resivoir… atleast on the S13… who knows where it is on those freaky S14’s :stuck_out_tongue:

Scotty - the lines into the exhaust are def not connected but I’d just like to find the valve/harness plug and play with it. My ECU still thinks this thing is connected to the more I know, the better.

I think Dustin is right… it seems to me like it’s an AIV-type unit where it takes fresh air and dumps it upstream of the cat to either help light it up quicker or to somehow clean the exhaust gasses? It’s somehow designed to pass Japanese emissions.

The HKS transfer kit is basically a relocation of the EAI unit and an extension of the tubing that is designed to work with HKS exhaust manifolds (because the stock EAI will not fit with an HKS manifold).

On S13s it’s located on the exhaust side of the engine, at the top of the head.

In this pic you can see it, it’s the gold diaphragm with the tubing leading out of it, just to the right of “CAM” on the valvecover.

Also visible here:


Booyeah - awesome post for what I wanted to know.


yeap and unfortunately the fitting on the turbo elbow interferes with the steering column

anyone know if removing this will affect the e test? i want to put the doc race manifold and tomei elbow on. also dose removing change gas mileage at all?