courtesy of Bob, The Auto Answer Man
I have a 1983 Mazda RX7, 110,000 miles. The car runs very good, but emits a bad odor (like a rotten egg). Primarily during start-up and when idling. It doesn't smoke at all. I have to smog test my car next month and was wondering if this would yield a bad reading. What causes this smell? I live in California.
The "Bad Egg" smell is actually sulfur deposits on the catalytic converter. This is making its way in through the fuel you use. One way to try and get rid of it is to switch to a name brand gas, use premium, and throw in a bottle of fuel injector cleaner. Then, go on a long trip down the freeway or anyplace where you can drive freeway speeds for an extended amount of time. Sulfur will burn off in the catalytic converter, but it needs to be hot. The name brand fuel is so there is no extra sulfur (the US puts a limit on the amount of sulfur that is allowed it fuel. It costs more to reduce it (sulfur is not added, but is present in the crude oil), and some of the off brands tend to have at or near the limit), and the fuel injector cleaner is to clean out the injectors and the rest of the fuel system. Since you are going on this drive, might as well clean it, too.
Bob, The Auto Answer Man
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