6.0 Surges

[PDA1]

I've got an 2003 Excursion with a 6.0L that has 92k miles. Oil was just changed The $$$ ICP sensor was replaced 2 months ago.

In recent weeks the engine has been surging while in drive at idle or below 1200 RPM.
The surging is infrequent and unpredictable.

No codes have been thrown....yet.

Any ideas what's wrong?

[capcalvin]

You need to check many things. Do you have any gauges? Scangauge II from autozone is well worth the money. I would start by checking battery voltage, FICM main voltage and logic voltage, ICP, IPR duty, Fuel pressure (can't be checked with scangauge II) Could just be bad fuel. Do you run any kind of additive? What condition is your oil?

[tuckman]

Replace your fuel filters and get a fuel pressure gauge. If it is still there get an Edge Insight or a scan gauge to check for codes and ficm voltages.

[Heathrm]

Did you replace the pigtail when you did the sensor? I replace both together, and 2 months later, had to replace the pigtail connector again. I also replaced, ford warrantied, the sensor again because it was free. Try playing around with the connector, wiggling the wires, and see if it does anything. If that does not work, try disconnecting the connector and see if it goes away. You might have gotten a weak sensor. Have you checked your ficm voltage also? There are videos on how to do it, just google it. Hope this helps some.