wrote:
Hello all,
today while flying from IA24 to MUT I turned my carb heat on and the
exhaust got noticably louder and I could smell exhaust. I shut the
heat off and opened the vents. Can the exhaust be repaired or are new
ones usually required. I'm going to have a mechanic look at asap.

Mike
PP-ASEL-IA

You sure don't want to fly that airplane until it's fixed.
Even with the cabin heat off a small amount of monoxide will enter the
cockpit, since those valves aren't very airtight, and a small amount is
enough to kill or incapacitate you. One or both mufflers will be
cracked, probably seriously. Cessna's inspection procedures require an
inspection of them every 100 hours, but it's often ignored; in Canada
we have an AD requiring it every 150. And we regularly find cracks.
You can get small CO badges from your aircraft parts supplier
that you stick on the panel; they'll turn black if there's monoxide
present and they're sensitive enough to be useful.

Dan