My Bonez HF CAT was sitting on my garage floor for the past year and when i lifted it up the other day i heard a noise inside, like something moving back-n-forth when i tilt the CAT lengthwise. The CAT has approximately 18k miles on it and it was perfectly good when i took it off the car a little over a year ago, plus I have the airpump connected. As long as the turbos still spool quickly, it doesn't overheat, and it doesn't make too much noise - what's the worst that can happen? Is it ok to use? Thank in advance for your help - Bill

 

I'd gently poke around in the there with a wooden dowel/stick and see if the brick it loose. If it's not, it could just be some random debris, maybe hit it with compressed air to see if anything comes out? If it is loose, I wouldn't use it. It can cause a lot of flow problems if it re-orients or if it starts to break up.

 

Great idea, I'll give it a try - thank you!

 

OK, so i poked around down the input pipe and everything felt solid. I checked the outlet and the screen looked fine. Is there a single "brick" inside or multiple "bricks"?

 

I personally have had three FD's come to me for work, which had BONEZ high flow cats on em. All which still were running stock seq twins. Anyway, the housing for the twins, w/the BONEZ cat on would actually glow orange ! First one I seen, I told the owner.....that glow, has got to go! Fab up a 3in. straight midpipe and the glow was gone for good. All these cars had 3in. downpipes and cat-back exhausts for the record. The BONEZ might have worked when new, but they didnt work when I seen em later down the road. FD needs straight thru 3in. down pipe and mid-pipe w/a nice cat back exhaust. If you cant deal w/that, get something else.

 

I just picked up a used one and had a similar problem. The heat shields were pretty rusty and had started to come apart at the welds. I pried them apart and blew air through them. A bunch of chips fell out. After that the sound was gone.