Fault codes P171/4 lean fuel trim

[martins]

Has anybody experienced these fault codes on a V6; fuel trim lean left and right banks?
Immediately comes back if codes cleared, no sign of air leaks at throttle body. Just wondered if anybody has experienced this before I take the manifold off and look further into it. Car runs fine apart from fault light on dash all the time and sometimes wont rev over 3000rpm.

[BuckMR2]

Bit late but if youor anyone else has a a similar problem check the breather pipe connecting the cranckcase and the inlet manifold.Takes under a minute.
Remove the 3 screws holding the large plastic engine cover on.
The pipe is to the left of the throttle body and is about 8 inches long and around an inch in diameter.Its common for this pipe to split unseen underneath.

Jaguar have improved the new pipe with a much sturdier one.
Mine had similar probs to yours ie not revving over 3k and engine MIL light on.
New pipe is around £5 and cured the problem.
Engine MIL then extinguishes itself after at most 3 cold-hot start/stop cycles

[martins]

Thanks for the info, you were spot on. Already checked the breather pipe but only from the top where it looked OK, took it off thanks to your info and there was nothing left of the underside! Made up a new one, cleared fault codes and been running for weeks now with no reoccurance.