rough idle???

[jobaa]

lately i've noticed a bit of a rough idle. the truck runs fine while underway probably because i can't feel a problem at speed, but at a stoplight it will idle rough but only sometimes. it goes between smooth and rough when sitting at the light. any ideas? i haven't scanned for codes yet but i will. thanks in advance, john

 

[BJS]

rough idle can be a wide variety of things ranging from oil showing its age and wear to UVC Harnesses, VC gaskets, IPR valve or ICP sensor, back to simple things like an air filter.

The first thing I would suggest is if you have more than 3-4k on your oil then change the oil and see if that fixes the problem.

 

[jobaa]

i just changed the oil a couple of weeks ago so i don't think that's it. i scanned it and came up with 1211 code which i think is the fuel pressure regulator. could that be it?