a rattling metallic noise startedcoming a few days.When i took it to the mechanic he took out the Heat shield .. didnt solve the problem ... he then said i need a new cat converter , so fixed a new one , after that ... just a few miles from the garage noise started coming again but was very low ... also , the very same day 'check engine' light came on. Called the mechanic and he said because its a new cat converter,its more efficient than the last one thats why the light came on ,and about the noise still coming he said it shouldnt come as its a ne cat converter, he suggested somethig is wrong with the silencer,but its exactly the same noise as the first time,if previuosly it was cat converter how come this time it is silencer ?. it will go away automatically after some time. Today i noticed that the noise is getting louder , so i am back to square one with money spent on a new cat along with the 'check engine light' and the same noise as i was getting before.
BTW i have a 1999 Civic 5dr hatchback 1.4i (I live in UK)

Any helk would be appreciated.

 

hrmmm...I can understand thinking that its the cat...many times that's what happens when they go bad...I've witnessed it on 1/2 dozen or so....but him telling you that its throwing a code because it's more efficient is retarded...

Usually when the cat goes bad, along with a rattle, you'll notice a decrease in performance/mileage...butdont thinkit would toss a CELon a95...pretty sure the o2 sensor is in front of the cat....

 

Thanks for such a quick response, so do u mean to say that the new cat conveter that i got is faulty ? shall i get a replacement ? actually i bought it myself.

So what about the o2 sensor ? you mean to say that the CEL is because of that ? Did he not install it correctly or is that gone too ?

 

No, I'm not sure why you are getting a CEL...I'm saying I don't believe a bad converter would toss a CEL on your car (but I am not certain) I am pretty sure the o2 sensor on your car is in front of the converter so it wouldn't read the emissions past that. So if your car is just now tossing a CEL then something else must have happened.

As far as your new cat....I dunno...I guess its possible to get a bad one out of the box...was it a cheapy? Really hard to say since I can't hear the noise. Maybe you could make a video...and when some of the other people here wake up they can have a listen and maybe provide some more/better advice.

 

i know the sound would be at a different location, but did you check the other heat shield?

 

still sounds like a heat shield problem to me as well..i would check em all.

 

Ill try to find out the reason of the CEL andlet you know. Well it was a cheap one cost me around £76 and i guess original honda one costs £200+ if i not wrong.

Well ill try if i can record the sound with my mobile.

 

other heat shield ? how many are they ? i thought there was only one . so where is the other one then ?

 

it's over the exhaust manifold

 

there is also one on top of the cat, and on top of the rear section of exhaust.