Shrapnell In My Exhaust?

[R33_Rob]

Today my '94 R33 GTS was driving fine.. no worries. Then when i went to drive home from the physio i had a strange sound comming from under my car. The sound was was comming from middle (underneath the gearbox) or towards the back of the car. I noticed it when i was stationary (in first gear with clutch in) and in neutral with clutch all the way out. I could hear the sound most of the way home and i was driving in 50 - 100km zones. When i pulled up at the lights the sound was terribly loud. But when i raised the RPM to 1200-1500 the sound was gone.. but that really puzzles me. But then again I dont know if it was drowned out by the loudness of my exhaust because it is a 5" exhaust. So moral of the story is that I hear the noise whenever my car is on, but it is loudest when idling. I thought maybe my exhaust had come loose but i checked and it looked fine. Prehaps a screw has fallen into the pipe (is this possible?) Any help is greatly appreciated.

[RB30-POWER]

Could be part of the catalytic convertor honey comb that has collapsed and broken off.

[R33_Rob]

is that expensive to replace?

[R33S2]

Hows the boost, is your turbo OK? Too many bits in that area to pinpiont just the zoorst.

[R33_Rob]

Its a non turbo. It has virtually no engine mods, except for exhaust, pod filter, strut brace. Does that narrow it down?

[R33S2]

Not really it could be outer gear box related get it on a hoist or a least a pit of some sort and find the bastard it'll drive you nuts or possibly break and do more damage, then again it could be just a cover of some sort and nothing too bad at all.

[R33_Rob]

yea, im definately having it checked tomorrow.

[R33_Rob]

i forgot to mention, recently i have had a "bit more than usual" amount of white smoke comming out my exhaust pipe. And 4 days ago my car nearly stalled when i tried to start it. Normally it starts perfectly 1st time every time

[R33_Rob]

BUMP

This morning it only made the weird sound below idling point (below 800RPM). This occured when i would slowly change gears without giving the car any gas

Edited June 20, 2006 by R33_Rob

[Craved]

turn the car off, and kick or hit the exhaust gently with a mallet... if it rattles then your Cat is broken and you'll need a new one..

[R33_Rob]

Took it into an exhaust place today. I drove it up on the lift, and within 10 seconds they told me it was the cat. Thanks for your help fellas

[RB30-POWER]

Should pick up some power again once its replaced and there is no blockage.