So I have been working on a 2000 TJ with 4.0l. I rebuilt motor and had timing issues. After posted issue on here she started right up. After a day or 2 of driving she kept throwing codes for misfire in cylinder 2. It would always set at around 2000 rpms and run like crap - no power, sound like a diesel engine. I tried new spark plugs recommended by forum, replaced coil pack and replaced crank sensor. I got frusterated and took to a local repair shop. While they were looking at it a loud noise developed in the head. It was shut down and I towed it home to take head back off. Upon pulling the valve cover I found a lifter on the second cylinder was extremely soft allowing a lot of movement. It is the 4th lifter back from the front. When I rebuilt motor I replaced the lifters with sealed power brand from advanced auto. Could this have been causing the misfire or did this just happen by chance?