So did a search and I dont see anything resembling this that I can find.
After highflow cat installed the exhaust is noticeably louder. Under hard acceleration probably in upwards of 4.5 or 5 k I get a loud, fast, annoying vibration from the back interior. It almost seems as if it is from the exhaust pulse, but on the inside. This is also after removal of the bose wave system and taking out the spare tire. I put the spare tire back in, but noise still there.
Any ideas?? Someone else I am sure bad this before.??

 

It's probably something loose back there that's rattling. Once your car starts being THAT noisy new stuff will start to rattle.

It may be something behind one of the panels that was OK before but now is rattling.

Dale

 

So what your saying is.... just start looking lol.
This may or may not take awhile. Just curious as if it is something really common

 

I've had 2 stock catbacks on my car, neither of which rubbed anything. Both aftermarket catbacks (RB and Apexi) I have had on my car vibrated against something - either the aluminum heat shield or gas tank. I had to take the heat shield off for the apexi and tweaked the shield for the RB.

The cat could easily have changed the alignment of your exhaust to bring it close enough to vibrate against something.

 

Did you leave a vibrator in the hatch?

 

I wish it was that easy

 

 

Lol.
I dont think it is heat shield. Does seem like right side though. I hope to driver her today or tomorrow so I will start eliminating things one at a time.

 

At some point on mine, the little metal cover that goes over the fuel pump wiring where it exits the fuel pump cover started rattling like that, so i slipped a little adhesive fuzzy-side velcro under it.

 

Check your jack assembly. Also check your heat shield around the catback. If its very close, you can probably bend it away so it doesn't rub.

 

Thanks for the help.