Yuck Fou Motorsport

Just fitted a Blitz Nur spec back box, de-cat down pipe to MY99 STi5, it sounds awsome but after driving for a bit it pop's and bang's when changing gear or slowing down proper rally style... is this normal?...

The Maf sensor was also changed as the old one was knackered...

scoobypete

I havent got a blitz exhaust...but my full de cat pop's every now and again when comming down throught the gears.

Pete

peachy wrx

mine does that with just a ninja back box

jason4656

forgive me if im wrong, but i seem to remember on old cars, this was due to the fact there was a leak somewhere?

Yuck Fou Motorsport

Think you may be right m8, there is a slight blowing from where the centre pipe joins the back box... time to get the ramps out and have a fiddle...