Q: fuel system status 2 closed loop using o2 sensor for fuel mix

Closed loop with feedback based on O2 sensor output is "normal" status. If this verbiage appeared alongside an OBD-II trouble code(s), I would need the specific trouble code(s), as well as a description of the vehicle malfunction, if any, to offer suggestions. Generally, if the check engine light is on, although codes can and should be read, there must be a follow on diagnostic during which components, circuits and so forth are actually directly tested. In particular no vehicle part can be condemned simply on the basis of it being "named" in a trouble code. If your check engine light is on, the recommended service is a check engine light diagnostic. If you request that service, the responding certified mechanic will read the codes and then test actual parts, that is perform a diagnostic, to find the fault and get this resolved for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.