1994 Ford Thunderbird O2 Sensor

Engine Performance problem
1994 Ford Thunderbird V8 Two Wheel Drive Automatic 115000 miles

I recently got a check engine light on my Thunderbird and took it to Autozone to scan the OBD II connector. The error codes that showed up were oxygen sensor bank 1 and bank 2 showing lean. I am aware that this car has 6 oxygen sensors. I have had them go bad in the past and just replaced the one that was bad. I am having a hard time beliving that both two of them are bad one on each bank. I am supsious of the MAF sensor is there any way I can check this no error code is stored for it though. Thank You