2002 Jeep Grand Cherokee OBD Code P1494 Issues

My car is putting out the code p1494 (evap leak detection pump pressure switch condition). I replaced the Leak Detection Pump and The code came back. I cannot find any vacuum leaks in the lines going to and coming from the LDP. Someone suggested checking the charcoal canister that is connected to the LDP but I have followed the lines until they disappear from sight past my rear axle. Where can I find this canister? What other methods should I try to find a leak? What else could cause this code?