I have seen several products for putting in the fuel tank that clean the cats and O2 sensors, any recommendations as to which is the best? Mr. Gasket, Solder One, etc??

 

I don't think any of them work, it's snake oil.

 

Since you'll probably be diving into this endeavor.... https://www.jaguarforums.com/forum/x...cement-195018/

 

 

 

Since you have the "combustion too lean" on both banks at the same time, the problem is probably in one of the engine components that is common for both banks.

The generic code list states:

• Damaged, split, perforated, dislodged, or hardened vacuum lines and/or hoses
• Splits, tears, perforations, or other damage in the inlet ducting
• Defective or stuck PCV valve
• Damaged oil filler cap on some applications
• Defective vacuum check valves or other vacuum operated components

The Jaguar code list states:
Engine misfire
Air intake leak between MAFS and throttle
Fuel filter, system blockage Fuel injector blockage
Fuel pressure regulator failure (low fuel pressure)
Low fuel pump output
HO2S harness wiring condition fault
Exhaust leak (before catalyst)
ECM receiving incorrect signal from one or more of the following components: ECTS, MAFS, IATS, TPS

 

 

If there is vacuum leak there, it can certainly cause problem. Whilst checking/fixing the hose you mentioned (full load engine breather), check that the small orifice in the hose connector/adapter on the cam cover is not blocked by crude (poke through with a thin rod).

 

 

The P1000 was not likely to change to P1111 with a fault like that but now has a chance.