Jump to content
Ultimate Subaru Message Board

Recommended Posts

99 OBW Trying to fix a P0400 code (EGR flow). When exactly should the EGR valve open to allow exhaust gas to recirculate? Is it supposed to happen on acceleration? Only when it's cold (outside temp)? Only when the engine is cold? I can make the valve open by sucking on the tube. I can't seem to watch it happen naturally. I've read that you should see it move when you make the engine rev. Is that true? Trying to see if the solenoid is bad. I removed the tubes while the engine was running. I didn't get any suction from either end (going into the solenoid or coming out). I cleaned out all the vac tubes (rubber and metal) that I could find, cleared out the computer, the CEL went out as hasn't returned (I've made more than 2 trips). Any advice? Thanks all.

Link to comment
Share on other sites

cleaning the EGR valve out is always a good idea.

 

on the passengers side strut tower there's a vacuum line going from a solenoid to the engine and close to the engine you'll see a small quarter sized filter in line with the vacuum tubing. i've seen those cause EGR lights to come on and horrible running/shifting problems. i'd go ahead and replace it, it's a $7 Subaru only part.

Link to comment
Share on other sites

CEL is back on again. I've cleaned the EGR valve. That little filter seems to let air through it just fine. Maybe I'll try to bypass it for a few days to see if that helps. I'm convinced, though, that it is either the solenoid itself, or the solenoid is not getting current when it needs it. Should I be able to trip the solenoid by hooking up leads from the battery to test it? It says 12V on the printing. Does it matter which terminal gets pos or neg?

Link to comment
Share on other sites

99 OBW Trying to fix a P0400 code (EGR flow). [...] I can make the valve open by sucking on the tube. I can't seem to watch it happen naturally. I've read that you should see it move when you make the engine rev. Is that true?[...]

Warm the engine, and run it at idle. Sucking on a vacuum hose attached to the EGR valve should cause the idle to falter (possibly even causing a stall) if the valve is okay and the exhaust passages aren't obstructed. With the hoses properly connected, revving from idle should cause the valve to move enough to be seen.

 

The following two links might be useful to troubleshoot P0400:

http://endwrench.com/images/pdfs/Emissions.pdf

http://www.vcertt.org/news/11-02.pdf

Link to comment
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
 Share

×
×
  • Create New...