The EGR valve on the 3.8L V6 engine is located on the left side of the engine, just below the throttle body. It is a round, black valve with two vacuum lines connected to it.
The EGR valve on the 4.0L V8 engine is located on the right side of the engine, just below the throttle body. It is a round, black valve with two vacuum lines connected to it.
1998 Oldsmobile Cutlass 3.1L V6
1. Locate the throttle body. It is a round, black housing located on the front of the engine.
2. Follow the vacuum line that runs from the throttle body to the EGR valve.
3. The EGR valve is a small, black valve with a single vacuum line connected to it. It is located near the top of the engine, on the passenger side.