Exhaust odor

I have a '92 Infiniti M30 convertible with 40,000 miles. It gets driven only 4 months a year, and then infrequently. The exhaust really stinks. The local dealer service dept. says everything is OK. No other car has such a lousy exhause odor. Any thoughts?

Is it rotten egg smell? If so it is likely the cat converter. Don’t just replace it, as there may be a problem with the car that caused it to go out. Maybe you car is running rich.

The odor is more of an enhanced typical exhaust as opposed to a sulphur dioxide smell. As the car sits unused for two to five months at a time (it’s at a vacation home) I add “gas stabilizer” before I leave. I try to use up the remaining gas when I return and refill with “pure” fuel. Do you think this stabilizer is effecting the exhaust. Unfortunately (fortunately) Utah does not have emission checks for re-registration, only basic safety. So I can not get an analysis that way.

Does the exhaust smell bad after it has warmed up and traveled a few miles? If not then don’t worry.

Considering the age of the car and that it’s driven so rarely you may have premature wear in the cylinders. Cylinders will rust if not kept wet, and perhaps over the years this has led to premature wear.

Has anyone done any analysis on the condition of the engine? Perhaps a compression check? Could you be burning oil and not using it enough to realize it?

How do you store the car?