[HMeeder]

Ooooh, carbon monoxide, not good.

Arlen; does the ride home kind of get a floaty, cloud-nine feeling? You really need to find that exhaust leak before the medics find you with your eyes rolled up into the back of your head and a big fat drool spot on your shirt.

Seriously, the heat exchanger may be rusted and banged up and not worth a damn for heating the car, but it should never be venting exhaust fumes directly into the car. You quite likely have a leak at the head/heat exchanger junction. I would replace the copper exhaust gaskets. They crush down and form a good seal when carefully and evenly torqued down.