inspection gasket

[woodysmom]

hey guys,

we replaced my friends worn out inspection gasket last week with a new one from nissan. He had a gas smell in his car so we tackled this problem first. The gas smell remains and we double checked the new gasket and for some reason, it was already cracking and had white residue on it. We just installed this new one a week ago and it's already messed up?! Was it just a faulty gasket or is there a deeper problem.

I've heard of people lacing this with silicon to give a better seal, how exactly do you do this?

Thanks