Do New Cats Whistle ??

[Focus57]

Got a new cat pipe fitted, when car gets hot makes a lot of whistling whining noises, can anyone tell me if this is normal please ??

Also can these be tricky to fit as am sure I can hear it knocking a bit ??

Cheers in advance for any reading

[Oldschool]

Not normally they can be tiny not sure of spelling , the noise u mite be hearing is a loose or missing blanking plug for a sencor or a loose fit either end, if it's got a dpf the pipe mite have come off they whistle if not fitted rite. Good luck 

[Oldschool]

If it's the Tdci the cat to manifold dose not need a gasket  but you have to make sure the three nuts tighten down evenly then hand tite the two bolts on the can that holds it to gearbox then the two bolts last  that connect to the middle section then once it feels set tighten the bolts on the cat to gearbox plate .