Isuzu 4HK1 6HK1 EGR Cooler 8-98068164-1. OEM-grade EGR cooler for Isuzu 4HK1 and 6HK1 diesel engines. Replaces 8-98068164-1 and 8-98068164-0. Used in Isuzu NPR/NQR/NRR medium-duty trucks and GMC/Che... Request a Quote for Europe — send your OE number, quantity and destination country for a trade price.