[Jerry Bransford]

Some 97/early 98 4.0L engines had bad valve springs installed from a bad batch. If this problem persists, that is likely your engine's real problem. The dealer has a TSB for it which basically just replaces the valve springs.

 

[Jerry Bransford]

Also, about the TSB... I'm not sure how they work, I am not the original owner, so could I still take it to the dealership and they would do it for free? Thanks

TSBs are not the same as a Recall. Recalls are always done for free whether or not the vehicle is under warranty. Recalls are for serious defects, usually safety related. TSBs are a Technical Service Bulletin that offers the dealer a prescribed method to fix a common problem and but are not free unless it's under warranty.

Your TJ is newer so it's hard to say if the weak valve spring batch problem is the source of your misfire as it was for my '97.

 

[Jerry Bransford]

Any suggestions or fixes for this code 43 I am getting??

Only the same one I already suggested to you above. There is usually no other fix for repeated 43 codes.