Multiple misfire code on 2003 dodge 2500 - Dodge Cars & Trucks

SOURCE: engine misfire code multiple cylinders, starts

There are quite a few things that can cause this.
Check your fuel pressure to start. 55 psi key on is good.
Also make sure it dosen't fall back down should hold at that psi with out engine running.
Aslo the intake's like to leak air around the gaskits which will cause a miss fire.
Aslo the mass air flow.

SOURCE: Multiple misfire code

i had same problem distributor gear becomes worn replace it and will most likely fix your problem they are known for distributor issues

SOURCE: 2003 Dodge Ram 2500- window master switch

Alot of times these switches get water from the rain coming in intoo them causing the contacts to short or not make contact at all, unfortunately they are not servicable but you may want to try spraying some electrical cleaner into the switch working the button at the same time this may help

SOURCE: 2003 dodge 2500 diesel backfires and destroys

Well, usually when a proper running vehicle backfires through the exhaust its caused by an excess in fuel building up in the pipe and igniting. Some newer diesle trucks will spray fuel into the exhaust to clean the emissions and reduce smoke coming out of the tail pipe. You could have a bent or sticking valve that is allowing extra fuel out into the exhaust, or when it went to clean the exhaust (If your model does that) the exhaust might not have been hot enough to ignite the fuel until you put a load on it causing the exhaust temp to jump igniting all the fuel in the tail pipe.

SOURCE: get multiple misfire codes. P0300 - P0303. If this

This could be a coil problem but i would start by changeing the plug wires and checking each plug.