My buddy has a 2003 Ford Focus 2.0 with 70k miles. His exhaust manifold seems to be leaking a bit. We are wondering if this damages the car at all… I think it does not, though lots of cold air could. I drive cars similar to Tom and Ray’s that leak exhaust like when I have eaten a half ton of pasta and then 20 canolis.
Yes, it can damage the car in one of two ways.
(1), depending on its location, it could affect the exhaust mixture in a way that will cause the oxygen sensor to get a false reading and cause the ECU to provide an improper metering. That could cause loss of efficiency and even operating problems.
(2) it could find its way into the passenger cabin, cause the driver to fall asleep (carbon monoxide is odorlaess and will put you to sleep) and cause the car to crash or perhaps even go off a cliff. Those things are hard on the body parts. They’re hard on the car, too.
Fix it. For safety’s sake.