In a message dated 98-09-22 10:48:58 EDT, joe@GREENCASTLE.DYN.ML.ORG writes:

<< I was talking to a auto parts shops owner in my local area and he told me
 that the reason why my heads on my vanagon are developing small cracks,
 to cause small coolant leaks, may be due to the storage and backflow of
 heat from the cat? He suggested drilling a hole through the cat, through
 the hcomb about an inch in diameter. I am willing to try this if it will
 prolong the life of the heads. Is this an okay procedure to do? Any
 responses appreciated!
  >>

easier to just remove the cat, and bust all that ceramic honeycomb stuff out
of there w/ a hammer and a pipe or something...then re-install the hollow cat.
i did it on my audi, and it just passed Pa state inspection, yesterday with
flying colors.

chris