I dont know why but Chinese homemad maf sensors are leaning mixture alwaysa cheeky update 3 months after the fact for anyone that comes across this. my issues on petrol were the maf. i was being a mug and clearly didnt inspect the original maf enough since it turns out it was a shitty chinese maf. once a denso maf was installed all the lean codes on petrol went away.
so in the end it was human error am now getting some misfires at 3k rpm. plugs changed, next up is coils. but only at 3k rpm, not 2k or 4k so very odd.