Hey everyone,

My 2000 XJ will idle normally for about 10 seconds, followed by a 1 to 2 second "lurch" in RPMs up to 1k RPM, then settle back down to normal. Has anyone else dealt with this? I assume it's some sort of vacuum leak? Any insight would be appreciated. I am also getting code p0456, but I don't believe they're related, as that's the EVAP system. I am probably going to have a shop smoke test it since I can clear the code and it'll take a week or two of normal driving for it to show up again (a very, very small leak I suppose).