First post here, hello world!

I've recently bought a 2015 1.6 with 21k miles and am really pleased with it apart from an intermittent fault:

Starts and runs from cold fine, good as gold. After around 20 minutes of running, when hot, it often suddenly begins to run lumpy between idle and around 2000rpm. At the same time the trip computer mpg read-out goes blank showing "- - -".  It's not a misfire, it's just lumpy / hesitant. It's an auto box so it makes pulling away rather uncomfortable, I can't rev the engine and slip the clutch.  If I switch off then re-start sometimes it persists, other times it re-sets for a while then starts again.

Had a look for loose electrical connectors and air leaks, found nothing obvious. Doesn't feel like an HT issue but I could be wrong.  I don't know which sensors generate the data for the mpg so don't know how to start checking them out.

All thoughts appreciated!

Is it generating any codes?

No codes. No engine light either.

Took the car to Ford Farnborough. It refused to fault. No fault codes.  Gah!  They did say it needed a new clutch, at 21k miles!

So Cargiant had the car back. They replaced injector no. 1, the coil pack, the HT leads and the clutch pack, for free!  After three weeks of good running it's started the intermittent fault again.  I might go for a little cry in the corner on my own.

This is exactly what I am experiencing now on my Mk2.5 focus 1.6 Ti-Vct,

Did you ever get to the bottom of this fault?