Quick cat question

[Gad-Westy]

Just peen poking around under my car to see if I could find the source of the odd noise that I get at full throttle. Initial suspicions were the flexi joint but it actually looks ok. I then noticed that the cat rattles. Is this normal or could this be the source of my problem? Noise only happens at highish revs i.e. 3500rpm +

[Gooby]

I am a fan of prevention rather than cure, can I suggest that you dont run the cat over in the first place.

[Gad-Westy]

Gooby said:

I am a fan of prevention rather than cure, can I suggest that you dont run the cat over in the first place.

[Arno]

Gad-Westy said:

I then noticed that the cat rattles. Is this normal or could this be the source of my problem? Noise only happens at highish revs i.e. 3500rpm +

If your at rattles then usually this means that the ceramic element inside the cat is breaking up.

May be a good idea to take off the cat and do a visual check. If it is breaking up then you'll need a replacement cat. Plenty to be found on Ebay (MGF cat works fine).

Bye, Arno.

[Gad-Westy]

Arno said:

Gad-Westy said:

I then noticed that the cat rattles. Is this normal or could this be the source of my problem? Noise only happens at highish revs i.e. 3500rpm +

If your at rattles then usually this means that the ceramic element inside the cat is breaking up.

May be a good idea to take off the cat and do a visual check. If it is breaking up then you'll need a replacement cat. Plenty to be found on Ebay (MGF cat works fine).

Bye, Arno.

Cheers mate, should have updated this earlier. The element was breaking up so for the time being I've removed the ceramic stuff altogether effectively making a decat. Will get a S/H cat off Ebay for MOT time and maybe a proper s/s decat pipe as well as I'm quite enjoying the pops and bangs. Its not as loud as I was expecting, is it possible I'm still getting some silencing effect from the old cat housing?

[Grinnders]

According to people more experienced than me (Cos @ sportomotive) the flexi-pipe has both an inner and outer hose. Frequently the inner hose (which is relatively fragile) gets damaged when exhausts are changed as you need a bit of play when disconnecting and reconnecting back boxes. A little too much can cause this to happen but with no noticeable external evidence. Apparently if this is the cause it is unlikely to do significant damage... presumably fragments get caught in the cat????

[Gad-Westy]

Grinnders said:

According to people more experienced than me (Cos @ sportomotive) the flexi-pipe has both an inner and outer hose. Frequently the inner hose (which is relatively fragile) gets damaged when exhausts are changed as you need a bit of play when disconnecting and reconnecting back boxes. A little too much can cause this to happen but with no noticeable external evidence. Apparently if this is the cause it is unlikely to do significant damage... presumably fragments get caught in the cat????

Taking the element out of the cat has cured my noise (and incidently my misfire) so it looks like the flexi section was ok afterall.