Ok, The stuff I read so far I found pretty useful but I still have some questions. But first I will start with the "issues". A couple weeks ago my check engine light came on, I checked it and it was a code 71. I wanted to be sure it was not a fluke so I reset the light and a day later it came back on. I kept driving and today all of a sudden at a light my engine seemed like it was not getting enough fuel(idleing REALLY hard and almost stalling). Had it towed home took it apart and I found this massive build-up. The EGR valve itself seems fine I used a screwdriver to make it open and close. Cleaned it all up, scraped the build-up out the head as best I could and it only helped a little but it's still idleing rough. Now for my questions. Whats with the build-up, and is it bad? Can I test to see if my sensor is bad myself, and how do I do that? I have seen how to test if the valve is bad but I have not done it yet.

 

From my experience, I have never replaced an EGR valve. That is carbon build up. Just needs a good cleaning. If it is a 22re, on my 88s build, I have it listed on how I clean it up and show what all is plugged. You are going to have all the vacuum lines clogged in most cases.

I take the Plenum off and take it to a carwash to get all of the build up out.

 

the valve was fine just some minor soot build up. In the pic that was from the engine block