I've put in a JDM engine a number of months ago and the engine has had a phantom misfire
it only happens when the fuel tank is above 1/8th of a tank, no matter what I do it wont with low fuel
the CEL flashes above 6k RPM to 9k with no loss of power
its a P0302
ive changed coils, plugs, injectors, cleaned the Eccentric shaft sensor, and the car has a new denso maf and done the brake stomp
the car has a cat delete and catback, oem intake, compression is around 85psi for both, using a piston compression tester with the shrader valve removed

 

I also have a super lightweight flywheel and clutch setup


Ogura Racing Clutch and flywheel that weighs 10kg total together

 

so on a lark I swapped out the ESS with a used one off my other engine and

it went from
90% of the time misfiring 10% not misfiring
to 90% NOT misfiring 10% misfiring

can someone please explain this? a friend of mine mentioned having to adjust the spacing of the ESS from the trigger wheel
but it literally doesnt look like I have any room to do that, the sensor just bolts on directly

 

If it's just the CEL blinking but you don't feel actual misfires nor is fuel economy abnormal(doing 100kmh steady in 6th gear stock everything gets you 10.5L/100km) then it's an ECU nonsense. It stores some ESS profile inside its memory and if it doesn't like it it will flash the CEL all the time even if the car is perfectly fine.