Metalling rattling after exhaust install (90 fc)
 

We've recently installed the Racing Beat full exhaust (header+presilencer+Catback) on the 90 NA Rx7 and something interesting is happening...

Whenever we rev the car, there is a very loud metallic rattle. This only occurs when revving the car with the clutch pressed in. When in gear, even at WOT, no rattling is heard.

We removed the heat shields and did not add any new ones, so we don't think this is it.

What do y'all think?

I think you should get under the car, safely, with a rubber mallet or dead-blow hammer and start taping on exhaust and surrounding components until you hear a rattle.

Hmmm I may give it a try... Really hope it's just something hitting the metal

Look and see if the 02 sensor is tight. I had this same thing happen on my rx8 and the 02 sensor was just rattling around

Perfect timing for your comment, thank you. I'm about to go underneath the car again and I'll check it.

Last time I was down there I noticed the hangers/bushings by the y pipe were all dry, and it was loose and it made a loud noise when hit with the rubber mallet. I purchased new ones and I'll install them today.

In case that wasn't it, it won't hurt to check the o2 sensor.

I'll update this thread if anything changes.

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So yesterday I had both the Y-pipe hangers replaced with brand new ones and I pushed some of the heat shielding away from any pipes and it looks like all the rattling is not gone.

On the heat shields I saw no signs of damage, so I don't think it is it.

The screech happens louder once the car is warmed up. I'll post a video with the sound soon.

Here is the link to the video. It usually happens at the end of the rev after the car is warmed up.

Either you have a pterodactyl in the glove box, or its just a common belt squeal.

I almost lost my shit reading this comment. I suspected it could have been a belt so I've purchased a new alternator one as it was being a little stupid, but last time I heard a belt squeal it didn't sound like I was murdering a damned pig.

I'll try that next and see how it goes lol

Lol