So you think you're going to impress her by picking her up in your BMW, huh? Unfortunately, your car's exhaust smells like Riker's Island on taco night. What's going on, and why is your car going to ruin your date? Three simple words: BMW Catalytic Converter. We've all smelled the number one symptom from a failed catalytic converter: a strong, sulfurous, rotten-egg odor. What you may not have notices are the more subtle symptoms of a BMW catalytic converter problem. Things like poor fuel economy, a decrease in power, and stumbling on acceleration usually precede the foul smell, but they can be mild enough to escape detection.

Your BMW catalytic converter is installed in the exhaust system, and looks a lot like a little muffler except that it's usually close to the engine. That's because the catalytic converter needs lots of heat to do its job, and the exhaust gasses are hotter closer to their origin. And in most states, if your catalytic converter fails, you're not going to be able to ignore it for long: Your car won't come close to passing an emissions inspection with a plugged cat. So if your car starts signaling that it's BMW catalytic converter is shot, get it fixed: It'll help your performance, and your dating life.

Root causes of this problem are a malfunctioning O2 sensor, plugged or inoperable fuel injectors, piston blow-by, leaking head gasket, broken or frozen choke or carburetor float, excessive cranking time, and repeated incidences of running out of gas.

Automotive Catalytic converter failure will typically fall into 4 categories:
1. overheated converter
2. Plugged Insides
3. Thermal shock or breakage
4. damaged or bent system

Thermal catalytic converter failure is most often caused when excessive raw fuel comes into contact with the catalyst, and "burns" in the vehicles converter instead of in the cars motor. The high quantity of fuel generates very high temperatures well in excess what of the converter was ment to handle, this thus causing meltdown of the ceramic guts or insides of the cars converter. The melted ceramic insides will then block the converters exhaust path. Sometimes you can hear a whisle sound when revving up the cars engine. This usually indicates a clogged catalytic converter.