Hi, I have another fault on my Jaguar:

Im getting the fault code P0420 "Catalytic converter inefficient, below threshold".

I mad acutally a fuel trim table to get a closer look into the engines fuel management.
Looks like I have a small air leakage, because of higher values in idle and low load conditions.
In higher load conditions, it is running ok (still + 3.24 on bank 1 and +0.78 on bank 2).
I have checked all connections and sprayed on them with brake cleaner, no issues found.
Replaced pcv valve, no change.
The car has driven 110000 miles.

What is about the carbon canister valve? Where can I find that one could this one be the root cause? So maybe it is not closing anymore?
I have read something about hair riss near the o2 sensors, which could also cause such issues?

If Im driving on the motorway with full throttle, it takes long time (> 300 km) to get the MIL light again, also when Im driving slower.
If Im driving over long periods just on high way, the bulb is coming very fast, every 50 km.

I could find quite a lot of oil in the intake manifold, this was my reason for replacing the pcv valve. There is also a second connection to the right bank of the engine. Looks like there is no pcv valve, just direct connection. Is this correct?
Any suggestions?
Thanks a lot in advance!

 

The charcoal canister is at the back near the fuel tank above subframe. My 2003 xj8 had 324tkm when I bought it and I know the previous owner drove to Portuga 2400km and backl probably overfilling the fuel tank so it pobably leaked intto the charcoal. I did over 45tkm with it until sold.
First Evap system is in the back by the canister.
the other one is front left behind tyre and wheel well liner. First time I earased the code id did not come back for about 500km then next time for mot it was back after 50km. Video of an xk8 evap exchange can be found on youtube. I exchanged the O-ring (briddle)at the entry to the throttlbody and all was good for over a 1000km.
hvave an 3.0 xj6 2003 very basi car now barely 85.000miles .
currently have fluctuation after cold start. And sporadic restrited perf sometimes just seconds 5he disapearing . Since I chaged the 6 sparkplugs last year possible airleak . And typical throttle pos sensor and since radiator change a coolant temp sensor plug wire a little to loose .

 

evap xk8