Rattling sound from turbo side on decelleration


Type RA Member
Hello all. I have a MY95 STI RA and recently have been hearing a decelleration noise coming from the turbo side of the engine. When the engine reaches 2,500 RPM the rattling begins, and stops around 3,200 RPM. If I exceed 3,200 RPM and begin to brake, the noise again starts when I get back to 3,200. At first I thought it might be that the actuator spring had come loose somehow, and I am still not totally sure that is not the issue. However, I came across a forum post stating that the issue could be a catalytic convertor in the up pipe, but the only confirmation I could find was based on GD chassis Imprezas, or V6 GC8s. In a V2 GC8 like mine, would the up pipe have a cat? If not, does my actuator theory sound solid?
Thank you for your help.


V-Limited Member
Have a look at the thermal heat shield welded on the uppipe. When rust begins to progress, this shield isn't welded anymore neither at the top nor at the bottom of the uppipe and can generate ratling noise/vibration at deceleration.