Which emission control device eliminates crankcase combustion vapors?

The PCV (Positive Crankcase Ventilation) valve is essential for controlling emissions produced by crankcase combustion vapors. Its primary function is to allow these vapors to be redirected back into the intake manifold to be burned in the combustion process instead of being released into the atmosphere. This system helps reduce hydrocarbon emissions, improving air quality and engine efficiency.

The EGR (Exhaust Gas Recirculation) valve, while also involved in emissions control, primarily recirculates a portion of the engine's exhaust back into the intake manifold to reduce nitrogen oxides (NOx). The oxygen sensor plays a critical role in monitoring the oxygen levels in the exhaust gases to optimize fuel combustion but does not handle crankcase vapors. The fuel pump is crucial for delivering fuel to the engine but does not have a direct role in controlling crankcase emissions.

Thus, the PCV valve specifically addresses the issue of crankcase combustion vapors, making it the correct choice for this question.