I don't smoke so I'm not worried. But I HIGHLY doubt it. Regarding the potential negative effects of de-snorkeling Pedro (
http://www.pedrosgarage.com/Site/Technolab.html) told me:
"There are no cons on the '99.
It's a great mod.
Just pull out the snorkel.
No need to add mesh.
I de-snorkeled mine in 1998.
No issue with MPGs either.
Happy Boxstering,
Pedro"