Well I have a 2007 X-Type 3.0. I am also a mechanic and I am stumped. I am getting a flight recorder error and a bank 1 & 2 lean error. I have replaced:
1. Throttle Body;
2. Plugs and Coils;
3. Fuel Filter (tested Pressure its perfect);
4. MAP Senor;
5. Mass Airflow Sensor;
6. PCV Valve;
7. Plenum Gaskets.

Still getting codes. I watch on the live data and Bank 1 & 2 are running lean? I don't get it it. I tested the injectors they are fine... There are no vacuum leaks that I can tell and I checked everywhere... Anyone?

 

GinoC, I would do a smoke test (either pushing it into the intake or smoking a cigar and gently wafting the smoke into the engine bay. This motor is known for getting a vacuum leak on the lower intake o-rings when the car gets up in mileage/age. Keep in mind that there are upper and lower gaskets.

The other issue I have seen people fight is either a crack in the brake booster line (look at the check valve near the brake booster) as that will get powdery and start leaking which can drive one nuts along with the connection where that line taps into the intake. The plastic connector that holds it in place can leak, resulting in a hard to find vacuum leak. After that, I would start looking under the throttlebody. I want to say that the plastic tubes down there will crack, leading to major problems. I want to say one is orange and the other is green. Had a car with similar problems and I found that to be the issue.

The final place I would look is the accordian going into the throttlebody. This has been seen to develop a crack in between the folds, leading to a major vacuum leak.

 

IMT's ?