Recently I've been noticing a distinct buzzing sound coming from my exhaust system (2001 Prelude SH - DC header, stock cat, GReddy cat-back) at high rpms when the engine is cold. I'll notice it usually above 3500 or 4000 rpms and only before everything has a chance to warm up. I also want to mention that the previous owner installed the exhaust system and had someone weld the header to the flex pipe - not sure of the reason.

The buzz goes away after the metal has heated up and expanded. My question is, before I take a look at it, I was hoping for some ideas on what to look for first. To me, it doesn't sound like a heat sheild, metal on metal, rattle. That's what makes me think it's an exhaust leak - although I'm not sure what one sounds like.

What do y'all think?

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2001 Prelude SH
1990 CRX Si
Hondas are an addiction

Check all your gaskets in between the different pieces of the exhaust system. The best way to check for an exhaust leak is to get under the car while it is running and listen for the sound. If it is only happening at 3500-4000 rpm then maybe get a friend to hold it steady around there while you listen. Just be careful while under a running car because a lot of parts are moving around down there.

Does an exhaust leak sound like a buzzing crappy exhaust system though?

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2001 Prelude SH
1990 CRX Si
Hondas are an addiction

that could just be something vibrating. i had a nasty rattle for so long, and i realized it was a piece of rubber cought in between the chassis and the pipingg. the person who put my exaust in used it to stop the exaust moving and it wore down from the heat and just vibrated.

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