EGR Valve

I have a '95 Lumina sedan. At high speeds the Check Engine light will often come on. Scan reveals EGR misfire - cylinder #2. I replaced the EGR valve (with a used one) and cleaned out the carbon build up in the manifold. Light continues to come on with the same code. What should I do next?

Replace the spark plugs. Also when you get the plugs, grab a can of seafoam. Its in a red and white can says seafoam on it. Ive seen it at advance. I dont know if all of em carry it, but you might be able to get it there. If not go to Napa. Read the directions on the can. Do that before you change the plugs. But still change the plugs.

That's funny, cause I get that code some times, and it stays lit, then I drive at about 90mph down the highway for about 10-12 miles, and it goes out for about 6-8 months. Hmmmm.

Did you replace the EGR base gasket when you changed it? Possible you are sucking air around the base, might not even be the EGR itself.

Did you replace the EGR base gasket when you changed it? Possible you are sucking air around the base, might not even be the EGR itself.

I did replace the gasket. The EGR valve that I put in was used but came out of a working engine. Someone told me to check the EGR modulator. Any thoughts?