Intermittent misfire

[J29UST]

Hello, new here after some advice please, have a 2022 1.2 turbo Sri premium on 63k miles, have owned it since new, now I know it's a 3cyl but it has always ran jearky been to vauxhall several times, never missed a service uses loads of oil as they do, now vauxhall cannot find why it like misfires and gives awful consumption figures, vauxhall have admitted a slight misfire in driving and they did change the ecu under warranty, always had new plugs every 10k,just wondering if anyone has experience of the same and what to look for next, just bought a tdi tining box yet to fit, hoping this may make it run smoother
Thanks in advace