Sulfur Smell coming from exhaust.

Apr 18, 2005 9 Replies
87 Chevy 350 EFI. Been noticing a strong sulur smell coming from the exhaust. Any ideas what could be causing this?

Uhhhhhhhh, no. Bad guess though.............

Doc

It's likely one of two things:

1) Bad gas with high sulphur content

2) Catalytic convertor is about to give up the ghost

Doc

You experienced sulphur smell from a really rich mixture before? I've only noticed the tell-tale gassy smell..............does the type of fuel play into it?

Doc

It comes from lead in the gas reaching the catalyst in the converter producing a rotten egg smell. It ISNT from the cat going out, it isn't from to much(or to little) gas, its from lead! I KNOW they don't sell leaded gas anymore! But allot of companies still have a minimal lead content in their gas. Running hard definatly doesn't help because it increases the amount of lead on the catalyst before it can be burnt away. That is the main reason the Euro-Trash sport compact junk driven by theses wet-behind-the-ear-daddy-leaches crank by and leave rotten egg smell behind...That is SO cool...

The factory converter in '87 far beyond SUCKED! If you must have one due to legalities, replace it with a monolithic design(straight-through) converter. You should still be legal and the poor choked-nearly-to-death truck will breath MUCH better and be very thankful.

The smell is from the cat that is no longer up to the job. On an 87, this may be because it is just worn out. On newer vehicles, it is often because of an over-rich condition that the cat just can't keep up with. H

I had this smell (I assume by sulfur he meant rotten egg smell) and it turned out to be bad O2 sensor.

I have a 2002 S-10 flexible fuel. I use E85 but I still get the sulfur smell. Turns out it was coming from the passenger side that usually carries a Budweiser aficionado.

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