X350 XJ purchase - early cars vs late

[Loose_Cannon]

Dodsy said:

That air leak , my money is on the rubber seal on top of the plenum which will throw an emissions fault on bank 1 and bank 2. Mine failed at around 70k and was replaced and is on the way out again now at 230k . Going to tighten it after xmas and see if i can get away without replacing it.

Take the engine cover off and you can see it , look for soot marks around it which indicates its leaking.

Thanks the codes (P1071/P1074 both banks lean) are a permamnent feature! At first the car hardly noticed but after 10k miles I have perceived it getting worse.

Whilst disassembling I have seen soot marks in the front corner of the left hand cam cover, and wondered if this could also be a problem?

This is the first car for a long time I have wanted to keep forever, but suspect its lifespan will be dictated by parts supply and the cost of diagnosing niggling faults like this.