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Originally posted by anythngbutgm
Under hard acceleration,

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It's hydrogen sulfide or H2S. It does not exist in the fuel or oil, which is why you can't smell it at the gas station. It does, however, come from the gasoline. Almost all gasoline contains organic sulfur compounds with sulfur levels ranging from 30 to 100 parts per million, approximately.

"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.

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Originally posted by anythngbutgm
:2: andreseng, you rock! Thank you so much for posting that.

"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."

All instances have been upon acceleration on inclines.

Sadly, my X was in a hefty collision back in August when some moron in a Taurus slammed into me at about 70mph and his front end actually went underneath the back end of the X. The force of the impact crumpled the Exhaust up underneath the vehicle. (He hit us so hard he actually kept going and stopped about 200 yds up the highway, car on fire and everything!):mad::mad::mad::mad::mad::mad::mad::mad::mad:

I believe everything was replaced from a new Cat back to the tips, so I think I have a brand new cat that needs to be broken in...:rolleyes:

Oh and I have a new found respect for the X, that thing took the impact VERY well. My wife and I walked away with only minor aching for a couple of days...

Thank you very much for your help guys :P




- 03 MDX - SBP Touring - HERS
- 02 Accord Sedan - Silver EX 5-spd - MINE

Am I anti-American? Nope, got an Ohio Accord and a Canadian Acura

Am I anti-GM? Absolutely.

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quote:

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Originally posted by anythngbutgm
:2: andreseng, you rock! Thank you so much for posting that.

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