ok so my brother has a subaru impreza wrx sti 2008 hawkeye and he has just fitted a blanking plate on the dump valve recurculator to see if it makes turbo flutter noises but in stead it causes a backfire on de-acceleration? anyone know why this is and have a fix for it?

did he remap it afterwards

 

nah i think he is planning on it

33 minutes ago, jude123412 said:

nah i think he is planning on it

to me the ecu is getting confused, you are meant to remap it when fitting a dump valve, some guy did a video of him putting dump valve on and it was running rough.

8 hours ago, jude123412 said:

ok so my brother has a subaru impreza wrx sti 2008 hawkeye and he has just fitted a blanking plate on the dump valve recurculator to see if it makes turbo flutter noises but in stead it causes a backfire on de-acceleration? anyone know why this is and have a fix for it?

I presume the blanking plate has been put in the turbo inlet pipe?, With the valve's recirculating rubber hose now acting as a vta?. 

If that's what you've done then u can't vta with a maf, it has to be speed density tuned.👍🏻