My mechanic put on my block off plate but he didn't run the bead of red permatex around the entire egr area. My smoke machine showed it leaking and when I removed it I found the lack of sealant. So I tried running a new bead of sealant and will let it sit 15 hours, then I'll smoke it again. I'm using a copper gasket and I put the sealant on both sides of the gasket. I was wondering how others have done it. I've heard they are hard to seal but I hate to spend $40 for a new EGR valve that the chip doesn't even recognize. Smoke leaked out of the old valve (blm's were 150) which is why I removed it. Thanks.