Ca18et runs bad/missfire

[Westerlund]

My s12 with ca18et has started to run really bad and missfire up to around 3250-3500rpm (dont know how exact the oem tach is)
It misses and spits up to that RPM range but when i hit 3500rpm mark it's like someone turns off a switch and the car runs great and clean from 3500 and upwards.

I have changed the plugs and coils/power transistors (to used ones) without any luck.
Any Good ideas on what can cause the issues?
For me it seems to be a signal issue due to the exact rew range it always run bad in and switches to run Good att the exact RPM every time.

I have read about transistor failures, that the car starts du run bad when the boost starts to come but for me it runs good on boost.

[s13eater]

air flow meter or throttle body switch.

[s13eater]

i had one that would tickover ok, then missfire on acceleration, then one that would tickover lumpy then pick up on acceleration, both air flow meters were fucked.

[CNHSS1]

AFMs a good shout, as is the wiring to the AFM which ive had fail.

if its revs based, could be voltage related, check earths to block and to ecu. Ensure battery is 110% good too.

try unplugging each plug lead in turn and seeing if that has any effect, do the same with the injectors

if it doesn't feel 'electrical' check fuel pump and filter, good be a goosed pump or clogged filter, restricting flow of fuel as the rom and fuel requirement rises

[Westerlund]

It was the o2 sensor, or what you guys call it?
I changed it yesterday and now the car runs great again.