335i Rotten Egg smell

[E90Company]

JB4 map 5, DCI.

After a few WOT runs I pulled into my driveway and the exhaust had a rotten egg smell to it. I have completely stock exhaust with all 4 cats and am running 100% 93 octane. What could this be?

Thanks guys.

[folgrz]

The cats are more than likely going bad.

Time to go full catless!!!

[piele_bps]

You have a dead mouse in the exhaust. Take it out toghether with cats. Go fully mouseless.

[BoostAddict]

May not have been your exhaust. Automatic transmissions smell funky when they get really hot. Otherwise, I agree with folgrz.

[SSO95]

Make sure your girl is wearing underwear next time she gets in your car.

[FRD135i]

Make sure your girl is wearing underwear next time she gets in your car.

Bahahaha!

[Sticky]

Usually a sign of a clogged cat.

[LostMarine]

I'm betting you ran your mouth to some other people and they egged your $#@!. Can't say I blame them.. or could be your cats

[BavarianBullet]

It's from a sudden rich condition, prob from the WOT blasts. Likely nothing to worry about unless it persists over a bit of driving.

from: http://wiki.answers.com/Q/How_can_yo...nverter_is_bad

"As the fuel burns, the organic sulfur compounds break down into simpler compounds. If the engine is running lean (more air than is needed to burn the fuel), the sulfur is likely to be SO₂, or sulfur dioxide. The catalytic converter can change this into SO₃ (sulfur trioxide), which then reacts with the catalyst to form sulfates on the catalyst. Over several minutes there is a build up of sulfates. If the engine suddenly starts to run rich (not enough air to burn all the fuel), such as when you stop at a red light, climb a steep hill, or brake hard to slow down, the chemistry changes. Now the sulfates are unstable and they react to form hydrogen sulfide, which is expelled from the exhaust pipe all at once. The high concentration is the reason for the bad smell! This effect is a common problem with new vehicles because the catalyst is working at a very high efficiency. However, as the catalyst gets older, the activity drops. Fortunately for us, one of the first reactions to be affected is the formation of hydrogen sulfide. So as the catalyst gets older, the smell will go away. It should also be noted that many catalysts never smell bad. One reason might be because the vehicle doesn't run lean for much of the time, or perhaps the catalyst has an extra component that reduces the production of hydrogen sulfide.