Horrible rasp between 2500-3k and 3500-4k.
 

This started a few months ago and is getting worse. I searched and read the other threads. It happened on my stock header and still on my new uel. So it's not the stock heat shield like I hoped. I checked the bolts on sound tube as well. All seem tight. It happens on throttle and off. Sounds the worst at 3800rpms. Used to not happen or I couldn't hear it in the upper 2k range.

It sounds very similar to the same sound my old integra had when the heat shield on my cat rusted. Are there any other heat shields on these cars?

I just tried to get it to do it on a cold start not in gear and it wasnt happening. Has anyone had this happen before?

Sounds like an exhaust leak. Have you tried smoking it out or using soap water at all joints?

Oh the good old rasp!

Rasp happens when the exhaust pulses do not line up properly and the exhaust stream cools too quickly through the pipe. Cooling too quickly usually means the exhaust is too free flowing - wrong pipe diameter, etc.

The key is tuning for the pulses...you'll get better sound quality and performance. When you have a system that sounds great, then add testpipes or headers - you disrupt the original design and possibly the components of the system cannot handle the increased or changed flow characteristics.
I had a 2.75 catted front pipe that caused some rasp. Installed another one with resonator and cat, and it moved it in a different rpm range. Planning to install another resonator somewhere to cut a bit more into it.

Otherwise, there might be something going on in the pipes (cat braking apart, etc)

Good luck!

What exhaust setup is making the rasp for you?

Had a Perrin 2.5 resonated catback on for 4 years. Stock everything else. It was doing it when my stock header was on there. It is just worse now. Maybe it's from rust on the front pipe or overpipe. My new headers been on there for over a month. It has gotten worse in the last week.

I'm not sure if any of you can hear it but I have a video of it now, doesn't come through great sadly. You can hear it at 7 seconds then 25 seconds when i'm letting off the gas and it's crossing 3800rpm. It's like a mechanical hissing sound. Clutch placement doesn't matter with it.

[ame]https://www.youtube.com/watch?v=rtCdEt-YdsQ[/ame]

Have you checked to see if the aluminum plate is rubbing on the exhaust manifold?

My Perrin CB got bad as it aged. I imagine the packing in it breaks down. It went from fairly adult to full on strait piped honda.