hello everyone, new to the jag. im looking into buying an 02 s-type 3.0. they are asking 13k with 48k miles on it. (Good price?) everything looks perfect except for the idle. when i test drove it i was stopped at a red light and the idle started dropping. it acted almost as if it was starving for gas. as i have no experience with jaguar before i'm uncertian what it could be. on the hyway it seemed to run great. although it seemed to almost hesitate sometimes while cruising at hyway speeds. however, that may have just been my imagination. any ideas? this is kind of deal breaker, cause if i can't fix it easily then i'm wasting my money to buy it.

my thoughts are:

clogged fuel filter
possible bad gas
low octane
just sitting in a driveway too long
bad coils

could there possibly be something else?

TIA