1999 Chevrolet Monte Carlo Owner's Manual - Page 300

yellowblue Scheduled Maintenance 100,000 Miles (166 000 km) j Inspect spark plug wires. An Emission Control Service. j Replace spark plugs. An Emission Control Service. j Change automatic transaxle fluid and filter if the vehicle is mainly driven under one or more of these conditions: - In heavy city traffic where the outside temperature regularly reaches 90_F (32_C) or higher. - In hilly or mountainous terrain. - When doing frequent trailer towing. - Uses such as found in taxi, police or delivery service. j If you haven't used your vehicle under severe service conditions listed previously and, therefore, haven't changed your automatic transaxle fluid, change both the fluid and filter. DATE ACTUAL MILEAGE SERVICED BY: 7-12