I have a 2002 Taurus SES with standard V6 Vulcan engine and had a very similar problem. It may have been the same code. It indicated a misfire on cylinder #3. The most likely suspects were spark plug, spark plug wire, coil, fuel injector, and other things in that order. Changed spark plug and still had problem. Checked ignition wire with meter and decided it was probably OK. Added fuel injector to fuel and still no change. Engine loped on start up and ran rough but cleared up and ran fine after a couple of minutes. Check engine light was on. Changed to shell gas and added fuel injector cleaner again and about 3 weeks later check engine light went out and engine seems to be OK the last month. I think the problem was a dirty fuel injector. Suggest adding fuel injector cleaner and using a good quality brand gas and see if this helps.