Concerning exhaust pipe movement

[Sutherland77]

I have recently put a new cat back on my 1995 automatic LS. I got under the car to fix it rattling against the heat shield. I used a hose clamp and it fixed the rattle, but I noticed a metallic scraping noise when I cycled through the gears. It turns out that the scraping noise was the exhaust pipe against the hose clamp. The whole exhaust pipe is moving back and forth about three quarters of an inch parallel with the length of the car. It has the flexible joint between header and cat. What are some possible causes of this concerning movement? Motor mounts? Exhaust hangers?

 

[Theasian]

The system is designed to flex between the header and cat that's why there is that domed gasket and spring bolts since it didn't have a flex pipe. What kind of exhaust is it ebay special, aftermarket oem style pipe? As long as all the bends for your exhaust are straight your exhaust hanger are likely the problems old worn stretching or missing hangers will make movement a issue. As for the clamp try rotating it around and make sure your head shield isn't bent

 

[Sutherland77]

Thanks for the quick respond. Ill order some new hangers, they do look very old. Its one of the cheaper ebay Spec-D systems, it definitely gave it some nice kick though. Could the excess movement be caused by the increase in flow?

 

[Theasian]

No exhaust flow dosing have any control over movement.