What is the EGR valve on a 1992 Chevy Caprice Classic?

The EGR valve (Exhaust Gas Recirculation valve) on a 1992 Chevy Caprice Classic, like in most vehicles equipped with this system, is a part of the emission control system. Its purpose is to reduce NOx (nitrogen oxides) emissions by recirculating a portion of the exhaust gases back into the engine's intake manifold. This lowers combustion temperatures, thus reducing the formation of NOx.

In simpler terms, it takes some of the already-burned exhaust gases and mixes them back with the fresh air/fuel mixture before combustion.

Finding the exact location on your specific Caprice will require consulting a repair manual or searching online for diagrams specific to the 1992 model year and engine (likely a 5.0L or 5.7L V8). Generally, it's located somewhere near the intake manifold, but the precise position can vary slightly.