Ford Repair: 99 Mercury Sable GS, mercury sable, vacuum leak

Question
I just bought this car from an individual and the day after the check engine light came on. I had a diagnostic test and it came back:BBLack of bank 1 02 transitions-lean.Explanation BBECM detected bank 1 02 at its lean limit. Probable cause BB1 - Misfire on bank 1, BB2 - vacuum leak affecting bank 1 only, BB3 - fuel injector problem bank 1 and BB4 - Engine mechanical condition. Dont understand any of this, please help and tell me if it is an easy fix or very expensive fix. Thanks, Rhonda

Answer
The diagnostic came with a code. If your having trouble deciphering it, your not alone. What it appears to me is that bank one sensor two is lean. That is the oxygen sensor.And yes, it is relatively inexpensive to fix. It is the sensor located after the catalytic converter on bank one exhaust.