[V8] idle, poor running, help?

[Barton Chambers]

> From: "Larry Schor" <lschor at westga.edu>

> My 91 V8qm was running perfectly except for an intermittent pesky high 
> idle.
> I replaced the ISV and the O2 sensor to no avail. Last week, the car
> suddenly felt like it lost 100 hp, would not rev above 4000, and 
> smelled
> like sulfur.

These are classic symptoms of a seriously clogged Catalytic Converter.

Yer kindly ol' Unka Bart