DTC P0422 - catalyst efficiency below threshold. This is a fault code for the catalytic converter.
Possible causes: intake air leak, exhaust leak between the exhaust manifold and catalytic converter, damaged or faulty catalytic converter.
With engine idling, spray carb cleaner around intake manifold base and vacuum lines, if idle changes there is an intake leak.
With engine idling, stuff an old t-shirt or some rags in tailpipe and listen for an exhaust leak. If one is heard this will need to be eapired.
If above is ok, then the catalytic converter needs to be inspected- dents, holes, creases in the converter will set this code. If ok, then converter is failing internally and needs replacing
If there are no driveability issues at this time, including loss of mpg, then you can wait a few weeks. I wouldnt go more than a month though, as this can eventually lead to other sensors failing, thus costing you more in the long run.