Originally Posted by RDaniel2405
You should just replace the rubber grommets, but you should know on 2003-2006 that those are not the same part numbers (front and rear). The front is free flowing, the rear has a small valve to limit air flow for your EVAP system.
If it was me, and what I did replaced all 4 parts (2 rubber grommets and the 2 PCV elbow pieces) when I did my valve cover gasket. I also got my parts from the local dealer, I didn’t want to use the Dorman ones form advanced auto, the Dorman ones are different form the Mopar ones.
If you put the wrong PCV in the rear, your jeep will have a high idle, and the check engine light will come on. I know because I have tried it.
TJ's don't have the PVC system, they have the CCV system. There is no valve, it does have an orifice that restricts vacuum draw from the intake manifold.
I've had good results with placing an "O" ring under the CCV plastic port to prevent leakage...