The leak may be from a crack in the exhaust manifold. This generation
of civic has a chronic problem of having the cast iron manifold crack
right in the middle in between the 4 cylinder exhaust pipes. When you
turn on the heat in the car you will likely experience exhaust fumes
being vented into the car if this is the case.

If you take off the manifold heat shield you will likely be able to see
if you have a hairline crack.

Although the problem is relatively small, the repair costs are normally
around $1500 CAD. This includes a new exhaust manifold (around $900), 2
oxygen sensors a few gaskets and labour.

If you're lucky and can find a shop that has precision welding
equipment, and is willing to seal the crack, then you're looking at
approx $350-$500 for repairs. Just be careful not to damage the
existing O2 sensors because they are probably seized.


Peter H wrote:
> Hi Group: Hope someone here can help me with this question.
>
> I've got a minor leak in my exhaust manifold of my 2000 civic. I'm wondering
> whether I'm doing my motor any harm by not having it repaired right away. It
> doesn't seem to be affecting performance in any way, but I've been told by a
> mechanic that it's there and I think I can hear it.
>
> I'm also curious about the cost of repairing it. I'm in the Toronto area of
> Canada.
>
> tia
>
> Peter H