never solved problem light still on.since manifold replacement engine oil leak every time the car is turned off
check engine light on since2 years old buick replaced manifolds o2 sencer bad . on 2006 Buick Lucerne
sounds like you need a 2nd opinion and its to late for warranty on previous work
1 more answer , 2 more comments
Who is diagnosing this car ?
replaced 7 o2 sensers since bought I year old.Buick replaced manifolds still engine light remains on.and now has oil leak which it never had
Apparently the o2 sensors have not been your problem, what does the scan show in the way of codes. Have you had it scanned lately. Give us the codes and maybe we can help direct you to the actual problem. If it shows o2 sensor, do not replace another one until the issue for it to mention the sensor has been repaired.