rb20 code 21? hmm.

[two40guy]

kay so ive been having this problem for a while, when i first did my swap i had a set of yellow jacket coils, it started breaking up terribly under load, youd get to full boost and it would just spit and sputter and run like shit. so i said hmm maybe my gap is off but my gap was fine but for shits and giggles i put it down to about .025 and it revved out but you could feel it kinda go between pulling hard and lagging up to red line, so i pulled the plugs and gapped it to .020 and it would pull hard and not skip or anything but it made my idle iffy.. not terrible just a little skip every now and then. so i decided i didnt wanna cover my problems up with running a lower gap so i upgraded to ls2 coil packs, got em in and it runs good but then i remembered i never gapped the plugs back up. so i gapped it to .035 and the car does the same thing.. breaks up really bad high rpm.. ive noticed since ive done the ls coil swap ive been getting a 21 code from my ecu but i did eliminate my ignitor? could that be way? ran fine on .020 gap but anything bigger it just skips and runs awful pulling through gears..

stock 10lbs
fmic - checked for boost leaks none
stock fuel pump- been running it since my swap and it has good fuel pressure
stock injectors everything

maybe fuel pump taking a shit?

[Yellow4g63]

Your running a stock KA fuel pump? Do you have a wideband hooked up at all? Check your grounds or find the fsm and start doing the checks per the FSM. It could be that those coils suck.

[two40guy]

no way, the idle and stuff is wayyyyyy smoother. and the pull is way smoother until it starts to break up. thats why it sucks. it gets really bad, like i can mash it to the floor and it wont really move just spit like its got a bee*r flames pops and everything haha

[two40guy]

anyone? starting to notice more and more it only does it when the motor is cold, once the car warms up it'll pull with little to no hesitation. im boost leak testing it again tomorrow. but i dont know i cant think of anything. also when its cold ill go to drive it and itll drive normal and then just fall on its face like you can actually here a difference on how it runs up to about 3k. almost like it just hits a dead spot.

[sk8rfreak345]

ever figure out what it was? I'm having the same problem with my ka.