Rough Idle issues

[Mr.Fork]

I did a bit of searching and didn't find any issues that seemed to match my problem exactly. I have had my sport trac for about 2 weeks and over the past 2 days, it went from having a smooth idle to a small shake. It is barely noticeable on the tach but you can feel it in your seat enough at a stop that it is annoying. I used a code reader to look for any codes but nothing has come up although I have driven about 100 miles since I noticed it. I get a brief second of hesitation when I hit the gas as well. I see what looks like some oil seepage around the PCV but as far as I am aware, pcv issues usually will give a code. Does anyone have any input?

 

[Kjhadfield]

I think most would suggest to clean the following and see if that clears up your idle. Air filter/maf sensor/throttle body/iac valve. Have also heard that just cause the cel doesn't come on doesn't mean there won't be any codes stored, don't know if that would leave out pcv issues. You could pull off the elbows and inspect for cracks or I even heard spraying intake cleaner near area to see if idle changes due to a leak. Not sure if oil "seepage" would indicate a stuck pcv valve or not. I went ahead and replaced mine just as preventive and although the elbows look ok, the valve (when shaken) didn't rattle as much as the new. I'm guessing not rattle or little would indicate a stuck valve? Maybe someone else will chime in if I'm wrong