Forcedair1 (and others)...

This entire "getting old OBDII cars to pass AIMS testing conundrum" is most certainly NOT just a Jaguar problem. And the requirements keep getting stricter. Which means the EVAP purge and other systems keep getting more complex. And there's a parade of millions of late 'aughts' and early 201_'s cars aging into component fatigue & failure.

Computers are great at reporting electrical or electronic problems they were programed to recognize, on stuff they directly connect to. Not so good at extrapolating a defined fault from intermittent mechanical degradation of devices they cannot directly 'see'. (ie. exhaust air pumps, vacuum lines, vacuum valves, check valves, etc)

Many problems begin as 'intermittent' as aging components begin descending into the end bellcurve downslope of their design life.
And intermittent problems take time and skill to capture.
And most auto repair shops are all about NOT spending 10 more seconds looking, or 5 more seconds thinking about a problem.
So thousands of motorists will be charged thousands of dollars for 'techs' to keep swapping parts until it works or you go to another shop.

This Show is just starting!....

(The above was NOT directed at that small proud brother(& sister)hood of true auto repair professionals, to whom understanding & maintaining these complex beasts is an avocation. You know who you are!)