Just had a catalytic converter fitted to my car and at motorway speeds seems louder 

Presumably an aftermarket/pattern part rather than genuine replacement?

If so, that generally goes with the territory. Thinner walled construction for cost reasons.

They wonted a 1000 for skoda one its fine till u get upto about 70 then its so loud is this normal then wen i stop after a long journey its making a puttering noise

😲

U got any ideas about the noise 

Go back quickly to them and ask what is this,

Is this a circo rhapsody?

You have an exhaust leak - what you are hearing is back-pressure from the Cat.  It will need attention.

This is what a hear after a journey 

Has your car hit anything in the bottom during the journey ?

It's obvious  there is a leak somewhere, what if you get down and take a look if any tube has been hanged ?

Mechanic had it on the ramp and says its fine but its defo not if i hold my had over the back box after a bit of pressure builds u can hear a hissing is thst normal 

No. Leaks! 

That's definitely not fine 😂🤣

 

Where does the hiss come from?

 

Really the exhaust should hold pressure right up till either you can't hold the pressure anymore or the engine stall (requires more force than just your hand).

No it sounds about the middle of the car its only dies the rumble rumble noise i posted wen i pull up at lights and the idle goes up and down 

Maybe there are more than one issues at the same time...

When idle plays it propably needs the lung cleaning or  adjusting and perhaps there is also a possible internal  collapse in the cat or any silencer?

Edited 12 August, 20205 yr by AkisVH

Had the car at garge today he said no leaks and had no idea about the noise 

Sorry what is lung cleaning

I think probably like many other members on here would say....

 

Take it to another garage and get a second opinion if that noise is directly as a result of work they have carried out and wasn’t there prior to taking your car to that particular garage then it’s either a problem with the part fitted or their workmanship and they need to fix it

So this is what the garage has came up with any ideas

Hi does anyone have a catalytic converter to fit a skoda octavia estate 1.6 mpi