1999 Chevrolet Tahoe Owner's Manual - Page 383

yellowblue Long Trip/Highway Scheduled Maintenance -- Gasoline Engines An Emission Control Service. (See footnote[.) j Inspect fuel tank, cap and lines for damage or leaks. Inspect fuel cap gasket for any damage. Replace parts as needed. An Emission Control Service. (See footnote[.) j Inspect Exhaust Gas Recirculation (EGR) system as described in the service manual. An Emission Control Service. (See footnote[.) j Inspect Evaporative Control System. Check all fuel and vapor lines and hoses for proper hook-up, routing and condition. Check that the purge valve works properly, if equipped. Replace as needed. An Emission Control Service. (See footnote[.) j Inspect engine accessory drive belt. An Emission Control Service. j Replace fuel filter. 7-33