Dodge Repair: 03 ram ignition, dodge ram 1500, modual

Question
QUESTION: I have an 03 dodge ram 1500 5.7 4x4 qc 74000miles my problems started when i ran low on gas, the truck started running real rough so I went and got $10 dollors in gas... no change, then I noticed a p0300 multicylinder misfire so I changed plugs,wires,and put in fuel injector cleaner well after 2tanks of gas and a remanufactured pcm still no change all cylinders seam to be getting spark and fuel pressure is at 45psi. I pulled the plugs today and noticed that cylinders 1,2,3,4 the ceramic centers are black and cylinders 5,6,7,8 are white like when I first installed them. (the truck feels like its running on 4 cylinders real rough) I checked all the connectors and they seem tight. What could the problem be?

ANSWER: check compression

---------- FOLLOW-UP ----------

QUESTION: I checked, cylinder#1=160lb #2=162lb #3=165 #4=155
Last night I took apart the fuel rail and cleaned it out also removed the valve cover on the cylinder#2 side to check the rockers and all looked fine. someone told me that this truck, in addition to the ecm also has some sort of ignition noise filtering modual... if so where is it?

ANSWER: ahh no noise filtering  the PCM it self does it by making its own ground.Have u replaced the plugs then?

---------- FOLLOW-UP ----------

QUESTION: yes, plugs,1-coil,cam,crank,map sensors were replaced. the answer you provide me on this next question might just point me in the right direction... There is a plug with 4 wires behind the cover under the steering colunm which isn't plugged into anything, 2 days before the problem started i installed a trailer tow plug and had probed one of the wires in this connector which affected the gauges on the dashboard and the truck stalled, I just restarted it and it ran fine at the time so I didn't think anything of it, what is this plug used for??

Answer
when u replaced the PCM was it with a Chrysler reman or did u just get one from some where? The plug i think u are talking about is from the skim system   if u dont have a gray key then u wont have the module that the plug connects into.

SENTRY KEY IMMOBILIZER MODULE - BLACK 6 WAY CAV CIRCUIT FUNCTION
1 - -
2 D25 20VT/WT PCI BUS
3 - -
4 Y135 20LG/BK FUSED IGNITION SWITCH OUTPUT (RUN-START)
5 Z110 20BK/GY GROUND
6 A14 20RD/WT FUSED B(+)