Cat to centre pipe bolt

[Mikebmth]

Hiya guys,

Need your advanced knowledge on this as need to find some bolts!!

On the rear flange of the Cat Converter to the centre pipe I believe there is meant to be 2 or 3 bolts, in mine there is one! Unsure if these are meant to be the sprung bolts or not??

If so where can I get them as can't find a supplier anywhere and if not what size bolts should I be using??

[Envoy CDX]

Rear of the cat to centre pipe, yes they are sprung. Front there this 3 bolts I used some nylocks from BNQ cos I was desperate. Held up for a few years.

[Robsey]

Okay - looking at both ends of the cat box.
Depends on which system you have fitted.

If two bolts -
Two sprung bolts at the front, which bolt directly to threads in the down pipe flange.

If three bolts -
Three straight forward hex head bolts size M8 x 30 (unsprung) held to the centre section pipe by three 8mm nuts.

You could use self locking nuts or anti-rattle / shake proof / star washers to prevent the nuts coming undone.

All bolts are still readily available from Vauxhall.
I bought a set of front bolts and springs from my local dealer about 12 months ago.

The rear nuts and bolts can be bought from any screw / tool supplier.

The sprung bolts are used at a flexible joint.
They use a bird's net like gasket ring inside the flaring of the joint.

[Mikebmth]

Cheers lads!! Appreciated as ever