What does the code FF23 really mean? It is titled "Oxygen Sensor Feedback (rich)" but when I read up the code in the Heritage manual it tells you how to test the O2 sensor and all the things that could trigger the check engine light. Much to much for my little brain, I did have another Jaguar fixer tell me that 8 out o 10 times the culprit was "old gas" causing the engine to run rich and activate the FF23 code. He said to add some "dry gas" and run out the remaining gas. delete the code, and add fresh gas and it should clear the problem. This some what fits because the gas in the tank is about 5 months old. Any thoughts???

Billwhis1