So, did a downpipe decat a few weeks ago and there's a definate whistle present that starts just before getting positive boost pressure and stays around just after when giving it medium to light acceleration. Hard to identify whistle from other noises at higher rpms/load. Does this sound normal at all for a decat. Been trawling the net and there seems to be just as many threads with people saying its normal for a decat as there are ones saying there's a problem.
Have tried pressurising the intake and has no audible leaks too.
Been trying to record the noise with the Gopro but it seems to struggle to pick up the whistle and overdoes all other present sounds.
This is the best i've managed to record. Occurs about 1-2sec into video
https://www.youtube.com/watch?v=fOhec1BPoY8