2005 Dodge Ram • 130,000 miles

I have recently discovered that my truck is misfiring. I do know that the catalyst system on my passenger side is out but the mechanic said I need to fix the miss fire before replacing it to prevent it from happening again. When it first started happening I was on the freeway and it started stuttering then when I had to stop at a light it died and my check engine light was flashing. After that I replaced all of the spark plugs and wires. But the problem still continues just not as bad. I can't even really feel it but my gas mileage is poor and when mechanics hook their computer up to it, it says random miss fire
February 1, 2013.

Have you checked the fuel pressure?