How long since a tune-up? 02 sensors are part of a tune-up Any applicable trouble codes? If your your fully obd1 compliant, you should be able to check codes, yourself. Check the coolant temp sensor.
To check for applicable mil codes, you use a jumper wire between A & B terminals at the 12 pin datalink connector. Turn key just till the dash lites come on, no further. Then the mil on the dash starts flashing, you count the flashes to get the codes. Your looking for two digit codes.