@Foxspeed it has been mapped and had this issue but then stock map was placed in for test purpose but it is still there. Was massive flat spot from 2500-3000rpm (even after remap) which is known to happen when precats are deleted or cats are removed, specially with Toyosports manifold (and I also have Akrapovic evolution). I would assume that stock map would be behaving like this or a remapped one (if maybe missed something) would do the same, so either map inside would cause it anyway, as it does now. Same problem. The car has rly modified breathing mods and stuff, here is a list: Flat spot (2500-3000rpm) and also this "bad idle and rpm drop / choke" appeared after the engine rebuild when modifications in "bold red" were added: -V6 Airbox + K&N panel filter -Vemo AIT sensor -Ported+Polished intake manifold -Ported head (exhaust and intake, intake not "mirror polished") -CatCams '402 (limiter at 7800rpm) -Lightweight flywheel (KTR) -Lightweight crank pulley (by Raptor) -Toyosports exhaust manifold -Akrapovic Evolution -Remap ________ Before the above marked "red bold" the car had remap at same tuner but everything was fine. After rebuild and above "red bold" mods, the remap was done again by same tuner. My questions / guesses here: 1) Could only Toyosports make my problem when mixed with all mods together? (wouldn't even worry about mentioned flatspot, but the idle choke and car turning off is what worries me, also sometimes it has struggle to start the engine in the first place). Also more AC power level I add, car will more likely turn of on RPM drop. 2) Headwork problem possible? But this wouldn't cause too much petrol being bumped to engine... 3) Faulty flywheel giving crank sensor wrong information and messing it up? 4) Map? (will be tested by the end of this week). 5) ECU just went to hell overall somehow? Most powerful indication and actually the only one (since on diagnosis it usually shows nothing, and sometimes missfire but with no cil num defined) is all 4x sparks are black and wet.