Catalytic Converter Question

I know that Jeeps have like 10,000 catalytics. Why? Dunno! Anyway, I went to the "Peppy" autoparts store to find this:


And apparently, Amazon is the ONLY place to get it. So here's my dilemma...

Whenever my overdrive kicks in, I get a sulphuric (rotten egg) smell. It's only when the OD kicks in. I used to use the above product and the smell would go away for about a year. I'm sure that one of my cats are going bad as I have 87,000 mi's on it. Please enlighten me as to the problem and/or solution!

The culprit ingredient responsible for the odor is hydrogen sulfide (H2S). H2S does not exist in fuel or oil, but it does come from gasoline during the combustion process. Nearly all gasoline contains sulfur compounds. Your converter is working very efficiently, the way it's designed. If the catalytic converter was at fault, then the oxygen sensor would set the "check engine" light. The smell is usually caused from gasoline brand. It can take five fill ups to clean out the smell from a catalytic converter. I would run the gas tank down to about a 1/4 tank, switch the brand and gasoline grade to a higher octane. The higher the octane the hotter and cleaner the gas burns.

The stuff you were putting in there was conditioning the fuel.

Hope this helps....

T-Case wrote:

The culprit ingredient responsible for the odor is hydrogen sulfide (H2S). H2S does not exist in fuel or oil, but it does come from gasoline during the combustion process. Nearly all gasoline contains sulfur compounds. Your converter is working very efficiently, the way it's designed. If the catalytic converter was at fault, then the oxygen sensor would set the "check engine" light. The smell is usually caused from gasoline brand. It can take five fill ups to clean out the smell from a catalytic converter. I would run the gas tank down to about a 1/4 tank, switch the brand and gasoline grade to a higher octane. The higher the octane the hotter and cleaner the gas burns.

The stuff you were putting in there was conditioning the fuel.

Hope this helps....

That's the best answer I've heard yet! I will try a new brand of gas and see what that does. I also added some STP fuel treatment to see if that helps. Thanks!

from what i have found out t-case hit the nail on head. i would also check for an exhaust leak, because you should not be able to smell exhaust in the cab at that speed.