I have a 2005 Ram 1500 4x4 with Hemi engine. Using the key-on/key-off technique I get some cylinder misfire codes. I currently have a misfire, so I'm not surprised to see the codes. I also had a misfire two years ago, and then changed all plugs and wires. Could some or all of the codes be left from two years ago? I have not otherwise cleared them.

The reason I ask is I'm currently getting P0300, P0304, P0307, and P0305. Two years ago I got P0300 and P0307, and the misfire made the engine run extremely rough. Currently the misfire is intermittent, and not consistent as it was the last time. At that time I replaced cylinder 7 plugs first since that code came up, and the problem went away. I later replaced all the plugs when I had time (if you've done this job you know it's time consuming) I'll most likely change all the plugs again, but will likely start on the ones throwing codes if I know they are all current (not two years old) codes.

 

I'm not sure if the codes clear, but the light goes off after a few days.

 

go to the local parts store and most have hand held scanners and will let u use them they will erese the codes and tell u wat they are

 

or just pull ur fuse panel under the hood and pull #23 fuse (PCM) turn ur key on untill all the lights are on and no more dings, then leave the key on and put fuse back in turn key off then back on and ur pcm is reset

 

Yeah, I would certainly reset the PCM and go from there. However, the CEL will go off under certain circumstances if the previous issue corrects itself for the time being. Usually it takes 3 fault trips to turn on the CEL/MIL and register a DTC.