So after a couple of years of occasional attempts to achieve perfect fuel trims on my 2002 XJR, it appears my goal has been reached. I didn’t even do anything to it lately; except change gas stations. We bought a new house in a new State and the closest gas station to my new house sells ethanol free gas.

 

Almost like the battery was off, which clears the trims.

Genuine trims are hardly ever zero all round... sorry to say!

 

It bounces around, it doesn’t stay at all zeros. It fluctuates between +5 and -2 while driving but when I stop and let it idle it settles to within 1 or 2 of zero all around, occasionally showing all zeros. I snapped a screen shot while I had the chance!