Been checking out this thread for a little bit because I'm throwing the same code as well for the EGR valve. I'm at a car dealership that has GM/Buick as one of its dealerships. I work at the Nissan part of said dealership and I'm trying to get as much info as possible before I get it checked/fixed. Thing is the CEL goes off and on by itself so that's why i'm thinking that's the issue. A tech that I work with at Nissan read the code but the guy that I had who knew GM's and would work on my car doesn't work there anymore but I know a few guys at our GM service who I can trust. Definitely sorry to hear your CEL came back on and hope you can get the problem resolved soon.

 

Well positively the code went out this afternoon on it's own, so now I get the fun of chasing an intermittent problem, oh yeah yippe lol, I hoping it was some loose carbon related to the changing of the valve, so I am going to pull it off and get some cleaner, and pipe cleaners and go to town cleaning everything as well as checking the wiring connections, as they say sometimes a loose wire will cause it to throw the code, and if some of the carbon build up is stuck in the vacuum lines it will also cause the code to go off (I have been doing a lot of research on this lately lol) there was even talk of carbon building up in the intake, but this mimics the egr valve failure and causes the code to go off. When I was researching they said that each shop charges a different amount to go inside and clean everything out, as it is mechanics special tricks and secrets, so I'm guessing they get a can of seafoam and pull the egr and spray everything down and clean it and hope for the best. There was also talk of a possible clogged catalytic causing the problem as well, I believe they were referring to the 02 sensors, as any of the problems surrounding what has been going on with my car, are not catalytic converter related, according to the research I have done as my car is not acting like the converter is plugged. If and when I get this resolved I will let you know what it actually was and how I got her fixed.

Ken

 

Word...From your response you just gave me a good amount of info to start with. I work at a car dealership but I work mostly by myself doing new and used car lot duties. I can do basic things and maintenance on my own car and time but I'm no mechanic. I'll keep this info with me when I go get my issue(I'm going to do a full checkup so hopefully that's all that it is)taken care of. And my CEL is still off. Has been for a few days. When the lights on, it'll be on for less than a day or two. It definitely stays off way more than on which is probably why I haven't gotten it looked at yet.

 

Check your gas cap as well, when they lose seal they create an air leak in the system and it will throw your cel light on especially if the light comes on shortly after filling the car up with gas.

regardless keep me informed with your progress, and if I figure mine out I will let you know.