Land Rover Repair: P2096 trouble code, vacuum leaks, catalyst fuel

Question

LR3 P2096 trouble code   Since more than 1 year ago, my LR3 2006 (v6) started to present the yellow check engine light, with the scanner that I have in that moment I only read the code "Fuel trim Error bank 1". Since then my mechanic did a complete tunning to the engine and checked every thing related, but almays the check engine light and this code have been appearing again.  I bought a new scanner recently and the trouble code indicated is: P2096 OBD (Description: Post Catalyst Fuel Trim System Too Lean, Location Bank 1).

Please your help, what could be the problem and what I have to do to fix it?

Answer
You might be looking for an injector problem, a vacuum leak, or an air meter issue. This is the time you need a more sophisticated tool to look at the live data from the engine so you know where to go next.  You need to see those various values to know what is off.  Without that you can do a smoke test for vacuum leaks but that may not lead you anywhere.  I would find a tester that can show live data, if it were me.