ok guy i have a 01 xj with all stock motor wise minus intake and throttle body spacer(all installed before i bought), my jeep popped a p0441 code a while ago so i replaced the gas cap. the jeep was fine for 4-6 tanks of gas so 1000+miles with no check engine light, drove it 13 straight hours to north carolina (where i moved to) and now it popped the same code yesterday. how do i fix this code without blindly replacing parts. is there a trick to checking for a vacuum leak? also the tank is 1/4 to 1/2 tank full so have not filled recently. I need this fixed so that i can pass the out of state inspection and emissions check. Thanks for any ideas or advice that you guys have.