In re-reading this post I have to agree that you probably have a CEL issue as well. If you have 02 sensor codes it should've light off the CEL and according to you has not. Do yourself a favor and twist the key to the ON position and see if you have a light in the cluster that reads "check engine". If not you have a couple of problems, the bulb is burned out or more likely has been removed, and you will need to address that issue as well as the cause of the codes. If you are posting lean running codes then, by all means, check it over for rotted rubber vacuum elbows (very common on these cars). I would:
1) Check the check engine light function and fix as necessary
2) Get the codes checked and cleared where you can
3) Check for rotted rubber elbows

Mark