[jolt2]

What you can do is take it to a shop that has a smoke machine to have it tested for vacuum leaks instead of guessing and throwing parts at it.

 

[jolt2]

This link will sum up what needs to be done. Read it carefully. Kia Sorento P0455: Meaning, Causes, + How to Fix | Drivetrain Resource

If you or the shop you take it to does not have the proper testing equipment and information about how to test the KIA evap system, then take it to a KIA dealer. Here is basic info on the system from KIA and the testing info..... Kia Sorento: Evaporative Emission Control System - Emission Control System - Kia Sorento XM 2011-2023 Service Manual

Finally, this is what can happen when you do not have the test equipment or knowledge to test a problem like this.... P0455 FINALLY SOLVED!!!