Knocking after Header install??

[fastfirebird2002]

I have noticed a knocking coming from underneath (sounds like its under the center console) sometimes under hard acceleration ever since my LTs were installed I thought it was the exhaust banging underneath the car but its pretty snug anybody else have this or know how to fix it

[Dr.Crash]

does it change with speed or RPM's?

[sunsetorangess]

Its your Y-pipe, you will either have to have it cut and weld in a new piece that is angled down, heat it up and bend it away from the floor or pick up a mufflex bumpstop...
J

[Dr.Crash]

i haed a problem like that and it was my y-pipe but it was hitting my tunnel brace

[fastfirebird2002]

Its your Y-pipe, you will either have to have it cut and weld in a new piece that is angled down, heat it up and bend it away from the floor or pick up a mufflex bumpstop...
J

Thanks I think I will check into the bumpstop someone said changing my mounts to poly would stop it as well

[Dr.Crash]

ya i changed my tranny mount to poly and noticed a huge difference

[fastfirebird2002]

I was told changing the motor mounts to poly would also reduce the banging of the y pipe