MIL lite kept coming on with a P0455 code retrieved, indicating a large leak in the evaporative emissions system. Tried changing the gas cap, without success. Also checked out some items referenced in some threads, such as broken or disconnected hoses, inop. solenoids, etc. All OK. I decided to back the car up on ramps, and have a look at the gas tank. There are two large carbon canisters, one on each side of the tank. The canister on the driver's side showed delamination of the sonic weld between the body and end cap of the canister, plus there was notable fuel smell emanating from the resultant gap. I fixed it by applying a bead of high-grade Loctite adhesive all the way around the gap (see photos of fix). Afterwards, no recurrence of the problem, and the car then passed the "e-check" required in my particular county in Ohio. I am surmising that Jaguar had a defective batch of canisters, where the weld would delaminate over time. At least that was the problem with mine.