It should be noted that the GT EGR valve and LX/DX EGR valve are the same. The difference is that the N/A valve is controlled entirely by vacuum while the GT is a combo of vacuum and electrical solenoid.
Your EGR valve is on the opposite side of the throttle body (intake manifold) It is slightly underneath the IM and above your alternator and looks like this:
Take the 3 (10mm head) bolts off and take the EGR valve out. Use a scraping tool and a can of carb and choke cleaner to clean the carbon build up from inside. Make sure you work the plunger back and forth as carbon will also build up on the arm of the plunger. When you're done cleaning, it should slide freely without sticking.
There are two chambers inside:
You want to clean all of the carbon out of both, it's usually alot. Use something to scrape along with carb and choke cleaner.
Notice the build up along the plunger arm^^^^^^
You can compress the diaphragm for access to the plunger by hand ^
You also want to make sure that the diaphragm and plunger will stay compressed under vacuum:
Clean it up, re install in your car, reset the ECU, and you should be okay provided the EGR valve and solenoid are in working order to begin with.
Warm your car up to running temp and run it at 2500-3000 rpm for 3 minutes and check to see if the check engine light comes on. If it doesn't come on, you could have a leak in the vacuum system, a faulty O2 sensor, or insufficient fuel injection.
