OK, there is a "drive cycle" that has to be performed before the cars computer will "self test" the systems in question. The manufacturers are generally bad at letting anyone know what the drive cycle is. The Jag dealer SHOULD be able to find that out though. I will look thru my literature this weekend and see if I can find anything to shed light on the matter. These are called readiness tests or sometimes readiness monitors. Ask the morons at the dealer if they have any master techs employed there, or anyone with emission experience. There has to be a specific set of conditions met, ie like 32 miles at 54 MPH, 2 min. idling... or some non-sense like that. The answer about changing computers is not an acceptable answer, unless they are willing to do it one their dime. Sheesh!