So how do I verify its the computer, because the dealer hooked the scanner up to it and all it ver says is random misfire ?

 

You have to eliminate all the other possibilities first. Computer is the last thing to get replaced.

 

if it says misfire then you need to change plugs out and re route the wires correctly ,doesnt have anything to deal with the computer

 

Check this in the DIY section: 2nd Generation Dodge Ram Parts Manuals

Also, start on the cost free things first. Save new PCM for last. If these things are bad, new PCM only flattens your wallet and you will still need to fix them.

1. Check TB and clean IAC (it gets junk built up in there)
2. Look down throttle body for signs of oil on plenum pan. Also, use a magnet to see if pan is steel or aluminum. If it is steel, plan on replacing with aluminum.. Look for sticky on plenum in DIY. You can but on ebay for $50, or other places as high as $80+
3. Remove upstream O2 sensor, and see if it runs better. You will get a code. This may indicate clogged cat. (caused by blown plenum gasket)
4. As referenced above, check plug wiring. There is a TSB on here that shows the routing. Pull plugs and check condition - replace AFTER plenum fix if needed.

Let us know what the results are.