The Standard Ignition PVS161 SI Ported Vacuum Switch is engineered to meet or exceed OEM specifications ensuring a precise fit and reliable performance in 1984 1985 Chevrolet S10 S10 Blazer GMC S15 and S15 Jimmy models Constructed with brass and high temperature plastic housing this switch offers enhanced durability and resistance to engine heat and contaminants Its specialized thermal elements are designed for improved performance effectively regulating the engine s exhaust gas recirculation EGR system By maintaining optimal EGR operation the PVS161 SI contributes to reduced emissions and improved engine efficiency addressing common issues related to EGR system failures This direct fit replacement part minimizes installation time and labor costs allowing for quick and efficient maintenance Fleet operators can rely on the PVS161 SI to maintain vehicle performance and compliance with environmental standards thereby enhancing operational efficiency and reducing downtime