My 99 Dodge Ram 5

Scan for codes and check fuelpressure first clean throttle plate on both sides as well as iac holewith choke cleaner. Check for vacuum leaks with choke cleaner

Did you clean throttle plate and then spray choke clear around intake for vacuum leaks? Also check egr valve for being partially open or partially clogged as well as holes where it connects

Were bolts torqued to 8 Nm then 16 Nm? Which woud l be 72 inchlbs then 144 inch lbs. Try retroqueing the inteake starting form center on both sides working way to ends. That is about the only thing I can think of. You could try shorting out cylinders to find whic one is missing then check injectors for ohms maybe one of those is bad. Or a bad plug/wire etc.

You coudl check for resistance but normally thowse two give you trouble after it is warm, because of high resistance. You might try wiggle test at connections as a poor connection can do the same.I wold check resistance on those and if high replace themowever I don'thave any specs so you shold check against new ones. But I imagine if youare getting ohms of 1000 or so that it will be to high.