I have scoured this forum for a thread describing my problem, but have not found one. Here is the issue with my 04 XJ8:

Occasionally, I start the vehicle and get the "Limited Performance" message and the engine light comes on. After engaging the vehicle in drive, it hesitates then suddenly surges forward, then hesitates again, then surges..., etc.

If I pull over, turn off the ignition, and wait a few minutes, the problem goes away and I can drive off with no further problems. Several days later, the issue comes back. The local Jaguar dealer has checked it out twice and claims not to have found any issues. However, my OBDII scanner tells me there are several problems:

1. P0171 & P0174: Oxygen sensors detect fuel mixture is too lean.
2. P0193: Fuel Rail Pressure Sensor Circuit High Input.
3. P0328: Knock Sensor 1 Circuit High Input (Bank I or Single Sensor).
4. P0456: Small leak in the EVAP system.

Now, the oxygen sensor on bank 2 was replaced in July 2010, and the bank 1 knock sensor was replaced in August 2010 due to a circuit failure.

Since the problem is intermittent, I suspect that it is electrical, rather than mechanical. Can anyone offer any suggestions as to what might be causing this hesitation/surge?

Thanks to all.

 

Fuel rail pressure problem ?

 

sounds like air problems, all are a result of improperly measured air. my recommendation...try cleaning the mass air flow sensor really well, maybe a quick swab of the throttle body plate and around the TB openings, if the air filter is remotely dirty...change it too. Check for any leaks on the air pipe while your the MAFS is off, then do a hard reset, and start the car a few times. My car got the reduced performance message (must be the earlier MY slang terminology) and lean code, cleaning the MAFS fixed it permanently.