I have a 99 dodge ram 1500 4x4 with a 5.2 magnum...so the problem I've been having is that the engine is idling rough and I'm having increased fuel consumption. I've replaced the pcv valve, spark plugs, distributor cap, idle air control, checked all vacuum lines and 02 sensors. I honestly cannot figure out what is going on so if you can give me any help I'd really appreciate appreciate it.

 

Sound like a vacuum leak potentially. Have you checked your plenum https://dodgeforum.com/forum/2nd-gen...um-thread.html

 

yes I've checked but the only thing I found was a vacuum line that goes into the plenum just under where the pcv lines goes in was not connected to anything so I don't know what it was or goes to so I just plugged it for now

 

Rough idle and increased fuel consumption most often means the engine is running rich. Find a OBD2 reader with live data and see what long term and short term fuel trims are, as well as O2 sensor readings.