96 Subaru, 125,000miles.

I'm getting a EGR code 0400 once in awhlie. I've been clearing the code and forgetting about it. Seems to happen more often at elevations of 4,000 to 6,000 feet.

I've checked the EGR valve for soot and cleaned what was there. After I warm the car up I can manually open the valve and engine goes into a stall at idle. When I rev the engine I can see the valve operate normally. What else could be causing the code?

No responses? Looks like I'm on my own here.

There are other tests to be made. Google Subaru DTC codes and check yours.

Make sure the small metal line from the EGR to the solenoid valve is clear also.

You can test the solenoid by connecting the green plugs under the dash and turning switch on. Listen for the clicking to confirm operation. Don't forget to unplug afterwards.

In the future please start with more specifics.ie Engine, mileage.

 

O.

There is a small metal tube leading to the EGR valve. When I had P0400 6 months ago (~142,000 miles), I removed the EGR and used a stiff wire to poke into this tube to clean out the inside. I reused the original metal gasket and the code never came back.

Sometimes a post will get pushed down the page by high traffic. I didn't see the original until just now.

 

I would have to find a factory service manual to look up what to check for that code in that year.

The engine is an EJ25, that's the 2.5 DOHC. I thought I was clear that the problem didn't seem to be with the EGR itself, which seems to function well. But with whatever else might activate the check engine code 0400. The system doesn't seem to know it's working at times, especially at higher elevations.