2001 Cherokee Sport 4.0 with p0455, installed new gas cap, found a few leaky hose connections and fixed those, but no cure. Is the Leak Detection Pump a usual suspect if the above mentioned are corrected but still throws the code?

 

I just started getting that code as well. About a month ago I had the radiator and head replaced so I was wondering if this code was related to that work. What hoses did you find loose ?

 

Same here with my 01, haven't found a fix yet. New head as well. Haven't tried a new gas cap. Wonder if the hoses that connect to the side of the intake and go up by the blower motor can be found anywhere,mine are all cracked and dry rotted