I replaced all spark plugs and a oil change and have a cylinder misfire cylinder four
COIL PACK OR INJECTOR
Spark plug wire or wrong spark plug gap.
Swap the spark plug and coil from the #4 cylinder to another cylinder, reset the trouble code and see if the miss moves with the parts from the #4 cylinder. If the miss moves then one of the parts you moved is likely defective. If the miss is still there then move the fuel injector to another cylinder and see if you can isolate the problem.
Looking for a Used Ram 1500 in your area?
CarGurus has 11,327 nationwide Ram 1500 listings starting at $1,000.
Search Dodge Ram 1500 Questions
Dodge Ram 1500 Experts