stumble/rough at light load 1500-2000 RPM

[JimmyM]

I have a 2011 XLT with about 42,000mi. In the 1500-2000 RPM range (really right about 1800) under very light acceleration or even in park (slowly bringing revs up), the engine has a very slight stumble. Idles smoothly, plenty of power otherwise. No highway or heavy load missing. Torque Pro shows no codes set.
I get fairly decent mileage.

I was thinking about swapping the plugs (2011s don't have the broken plug issue) just for giggles, but thought I'd check with the gurus here first.

Is there a "definitely get these plugs" plug you guys would recommend?

Thanks.

 

[Barjrob1972]

I had the same problem with mine although with many more miles. It's started stumbling at about 1500 rpm's when I was just lightly cruising through town. No codes and otherwise it ran fine and still got "good" fuel mileage on the highway. It eventually started missing at high RPM's when I tried to pass. A plug change and fuel injection system cleaning solved the problem.
I went back with factory stuff.
You might try cleaning the intake and butterfly.

 

[JimmyM]

I had the same problem with mine although with many more miles. It's started stumbling at about 1500 rpm's when I was just lightly cruising through town. No codes and otherwise it ran fine and still got "good" fuel mileage on the highway. It eventually started missing at high RPM's when I tried to pass. A plug change and fuel injection system cleaning solved the problem.
I went back with factory stuff.
You might try cleaning the intake and butterfly.

Thanks. I'll give it a try.

 

[James Meyers]

Had similar problems with 97 5.4. After changing and testing many parts. Found the TPS to be the cause.