2002 4.4.

As the title says, I have an issue with a missfire / hesitation on light throttle openings. It manifests itself after a few miles from start up and only seems present on very light throttle openings, mostly after slowing down from a reasonable speed and then applying throttle again.
To date I have renewed the plugs and coils, cats and the PCV system. I have smoke tested the inlet to check for air leaks and done a compression test on all cylinders. Air flow readings have been checked against a known good MAF. I am now running out of ideas and welcome any input. Its also worth mentioning its a duel fuel car running a sequential LPG system, the problem is present on both fuels.

Iam starting to think perhaps the throttle body itself ????