1989 Camry Check Engine Light

My 1989 Camry (4 cyl. auto trans. all-trac) has the check engine light on. Mileage is approx. 129,600. Diagnostic code checked with jumper wire reads 25 (fuel metering device lean) and 26 (fuel metering device rich) I got the codes from the owners manual. Can anybody help me as far as what should I check next? What is meant by fuel metering device? Has anybody had these codes? I would greatly appreciate any help. Thanks
Also, the car starts and runs fine, except after it is warmed up, the idle speed is too high. But if I tap the accelerator, the idle speed drops back down to normal. Thanks Again

Check the oxygen sensor.