n54 misfire only when on JB4 map

[Moofasa91]

Hello,

09 135IS FBO

I just replaced my plugs and started getting random misfires. Sometimes its 1&6 and other times its all cylinders. The misfire goes away and the car becomes smooth again after a restart or a code clearing. The misfires happen during WOT pulls. Say I'm cruising 40mph and floor it then I start getting misfires. This only occurs when I'm on a JB4 map. If i set JB4 to 0 then I get no misfires at all.
New NGK Iridium OneStep colder plugs (this didn't happen with the older OEM plugs)

Do you guys have any idea what's causing it?

[xQx]

The JB4 maps push your car harder than stock, so its likely a result of that rather than the JB4 directly.

Have you replaced the coil packs?

[Moofasa91]

Originally Posted by xQx

The JB4 maps push your car harder than stock, so its likely a result of that rather than the JB4 directly.

Have you replaced the coil packs?

Yes my coils and injectors are brand new. I have the Bimmer life coils.

[Jeff@TopGearSolutions]

Which specific plugs? Did you gap them?

It's common to find the misfires when tuned and not when you're stock.

[tracer bullet]

Originally Posted by Moofasa91

colder plugs

This could be part of it. Generally speaking if you are adding more power then colder plugs are the right direction to change. But there's a chance that you didn't need to change at all and this is detrimental. Keep it in mind.

[optigrab]

Originally Posted by tracer bullet

This could be part of it. Generally speaking if you are adding more power then colder plugs are the right direction to change. But there's a chance that you didn't need to change at all and this is detrimental. Keep it in mind.

Yeah i agree... who knows what FBO means should mean aftermarket turbos with big boost. I dont believe you need to change them with the stockers