another light load issue

[Pommie]

Around 60kph in 1st to 5th engine feels like it's hunting one sec then almost misfiring the next. All vac lines are good, nothing trapped or linked, plugs and air filter recently replaced. Gipro says it's in the right gears so I don't think gear postion sensor sending wrong signal. Haven't done voltage check yet. Almost feels like injectors could be leaking as opposed to spraying. No codes to read. Any ideas guys??? Give it a fistful and no probs. Nothing above 80ish. Just happens when commuting around town.