There never was a "cat problem", let me explain....
Each cat has 2 lambda probes, one on the inlet side and one on the outlet side. Lambda probes measure the amount of oxygen in the exhaust. In a car with a "closed loop" system they also indirectly measure the fuel air mix in the engine.
The right inlet probe gave an out of range reading, indicating that the fuel/air mix went out of range for a moment. The cause? Possibly there is an air leak diluting the gas mix out of range, or the probe malfunctioned or some other cause. Or just some dirt from the exhaust valve came off and hit the lambda sensor for a moment till it burnt off. There are many possibilities.
If the error message is from the downstream sensor then it is possible the cat isn't working. In my case the cat is fine.
Is that all clear?
The correct solution is to clear the error message and see what happens: if the error returns further investigation is needed, if it doesn't come back it is safe to ignore the first error message.
