2000 D16y8 pretty much stock. Car slightly sputters above 4k rpm but around the passenger side it sounds like a plastic bag is flapping around in the engine... any ideas of what it could be?

 

Last tune up? Have you popped the hood and looked around?

 

tune up was done about 20k ago and they were OE plugs. visually there no obvious signs of a bag or what could be causing the noise. it doesn't missfire at idle just when i floor it sputters a little then i get up to 4k and it makes the noise

 

when does vtec hit on this motor?

 

5700 if I'm not mistaken

5600

 

This happened on my old em when I first got I and I looked everywhere for the problem it ended up being the headers had a crack on the side and that would make the sound once o changed the headers the sound was gone and hasnt came back

 

I don't think it's that... wouldn't a exhaust leak tick all the time?

 

Easy enough to test for a vacuum leak.

 

Hi, I have the same problem in my 2000 civic ex, I tried searching for days for the problem but no avail. Did you ever find the problem? Mine starts at aroudn 4-5k rpm.