At a minimum, P1111 is deleted and replaced by P1000

 

Today I had new rotors and pads put on front, Asked my mechanic to check for codes because none were showing on the display and the car did not seem to perform as I wanted on kick down, The only thing he saw was that the fuel trim was out of wack and did a reset. All is back to normal now.. Hooray

 

I would suggest you monitor this fuel trim, the reset may clear any irregularities till a history is built back up. Most likely you have a air leak in the intake somewhere. But you don't post the code so we can't say which way. BTW if you do, start a new thread for replies.

 

As Jack said. Also, a dirty MAF sensor can cause the same "mixture too lean" codes to appear. (An ODB scanner that can display fuel trims in real time as you vary engine RPM can take you a long way in diagnosing things.)

Good luck.

 

Whatever problem caused it to go out of whack is probably still there, soon to return.

 

tech indicated no codes were present. He was unhappy with the readings, hence the reset. He also cleaned the mass airflow sesor

 

People are just trying to help explain how the car works..........

 

Yes I understand. I am a newbie to jaguar but have never been defeated by a mechanical device. Including British Leyland sunbeams, MG Midgets, and B models.
I know I am in a whole new world with the xk8 and appreciate all the help I can get

 

Going to remove the negative cable and see what happens first. Wonder what happens when I do what you described? Does it clear out residual power in the car?
Sincere thanks for your help.

 

That's the intention.
it discharges everything so the computers 'reboot' when the connection is restored.

 

After you remove the negative cable all the power is removed from various components throughout the vehicle. Touching the removed cable to positive provides a faster path to bleed off residual power sitting in different components. Another path to open for bleed off is to turn the key on after disconnecting the negative. There are different thoughts on how long to touch them together and how long to leave the key on. Remember to turn the key off prior to reconnecting the negative.
This us a broad catagory and everything is not gospel for every year and make. For example my 2004 XKR has 1 fuel pump and a different fuel delivery system from earlier models that had 2 fuel pumps...I had a 2001 XK8 and a 2004 XKR. Performing the reset along with an additional gear box control module reset and procedure made a great difference. I inadvertently did a partial reset on the 2004 and it caused some performance issues. I had to go back and follow procedures and it was better than before. Keep in mind across all the years of this group and specific differences between the XK8 and XKR verify the advice is for your year and model.