New member needs mechanics help

[Jboden615]

1998 XJ 4.0 automatic. Keeps throwing codes at me p0204,p0205 can play with injectors the codes will stop and it will run good but after 5-10 miles codes come back. Not always the same have gotten p0201 and p0203 as well normally not more than 2 codes at a time. So far I replaced all fuel injectors, new tps, had new plugs and wires on it. Also tried replacing the computer from another XJ same year and all but still got the codes. I don’t mind buying parts but this XJ needs a lot so I only want to buy parts I need until its running good. After that I plan to continue to buy and replace parts for reliability. Goal is to have it reliable for my son to drive daily, however I know he likes mud. Any help is greatly appreciate