I have a 2004 Honda Civic. Since last week I can hear loud noise and feel vibration when accelerating. Everything else is normal. No check engine light. All fluids are in normal level. I took it to a shop and was told the long exhaust pipe became flat in the middle where it went across the body frame. The whole pipe was supposed to be in round shape. Is that true? They said that replacement of this pipe can resolve the vibration and loud noise issues. They confirmed there is no leakage for the exhaust pipe. It seems to me the flat pipe still works to take the exhaust away. How can flat pipe be related to vibration and noise?
Thanks,

Ann

 

has it been raining or anything, just a question.

 

No raining. I did roll over some small rocks on the road last week.

 

Have you possibly hit a speed bump, etc.pretty hard and bashed in the middle section of the exhaust pipe? lol

If so, you could have possibly bashed the exhaust in, causing the flat part, and knocked a heatshield loose, causing the rattling. Heatshields are notorious for rattling. Also the exhaust pipe could be rattling against the underbody somewhere (caused by the damage to the exhaust pipe). I would get that exhaust replaced and see what happens.

 

I took that to a local Midas shop. They replaced that flat part and the problem is solved. The reason for vibration is because the pipe was pushed close to the car body, passing the vibration from the pipe to the body.

Thanks for all your help.

Ann