Mr Athena’s car farts. On occasion, we’ll be sitting in the car going somewhere, and a very sulfury, bad smell emits from the bowels of the vehicle. I’ve tried to blame Mr. Athena for the odor, but alas, it’s happened when he’s not even in the car, and I know it didn’t come from me, so I’m left with the belief that it’s the car. It does smell a bit like gas (the fuel kind, not the fart kind), but much more sulfury.
It seems to happen more in the winter than the summer, but maybe that’s because we generally have the windows open in the summer. It also seems to happen when we come to a stop, like at a stop sign, more than when we’re actually moving.
It’s the catalytic converter, which is an anti-pollution component in the exhaust, located near the muffler under the car. It’s not a sign that it’s misbehaving or anything, so no need to worry. Here’s a link on how they work:
The next time you have the car serviced, mention this and have them check the fuel mixture. If the car is running too rich (too much fuel) this smell can get quite strong. You smell it more when you are stopped because you don’t have the motion of the air past the car to carry away the odor.
Since it seems to happen more in winter, it is possible that you have a bad thermostat that is not allowing the engine to get to its optimal operation temperature. This would cause the car to run in a rich condition as well. It could also be something as simple as a broken vacuum hose.