Failing Cat - would it cause these issues
 

Hi all, it being a Bank holiday weekend my normally perfect 850 has decided to grab my attention by playing silly buggers!! Earlier this week I noticed a rattle coming from the exhaust when I started her up but it seemed not to be so noticeable after being warmed up. All was fine running wise until coming home friday, she seemed not as sharp as normal. Went to autojumble down the road(cancelled, ever get those days when everything conspires!) and coming home she suddenly lacked power but still ran. When I was about to turn left across the road into my road she gave up and died. Coasted into my road and tried to start, which after a lot of effort she did but stalled when I applied any throttle. Again got her going and crawled along not using any throttle, its an auto so just poss to move. Had a look around and the cat converter is very rattly, plus at this point the lambda light came on. Sorry for rambling but could these issues purely be from a failing cat? I have reset the lambda light and it seems to be running fine, blipping throttle does not stall it. It did sound very rough, as though the manifold or exhaust was blowing; any suggestions as I now have to try and get a replacement cat, the earliest quote from kwikfix is wednesday, cheers, Dave

Could be a failing cat yet, causing it to drop into limp home mode. How well serviced is the car, and I don't just mean oil/filters. Plugs, dizzy/rotor, ignition leads etc etc??

Please don't go to kwikfit, they are a pack of robbing ****

I service it myself for usual oil etc but all else is fine. I am not keen to use kwikfit and may not use them but order a replacement from rufe and fit it wednesday, just a worry about driving to work tuesday( I ave a lieu day this week).

Cat or exhaust silencer collapsed inside, blocking the exhaust gases will cause the symptoms you describe.

Salut!


Pookie

if it is the cat take it off get a pole that is a smaller diameter than the exhaust pipe and smash the cat to pieces (inside) then refit problem solved and cheap.

A bhp increase too lol

Thanks for responses guys. I too thought that bits blocking the exhaust flow would cause the symptoms but its always reassuring to pose the question. I will remove the cat today and see how bad it is, it will also give me the chance to order any replacement bolts etc. that I break. Are the joints a dry fit or will I need exhaust gum or similar????
Whilst tempted to remove the innards of the cat and refit it, I would rather replace it to make sure all works as it should, cheers, Dave.

cat
 

On the turbo side it is a dry fit. You can not use exahust paste as if it sucked through into the cat, it can damage it. You can use it on the other end of the cat, where the rest of the exhaust clamps on.

Regards

Stuart

Thanks Stuart, I'm half way through removing the cat at the moment and the connection to the exhaust side is a dry fit as well.
Any suggestions as to how to get the flaming sensors out?? They are resisting all efforts so far.https://www.volvoforums.org.uk/images/icons/icon7.gificon9.gif

Just to say I have managed to get both sensors out in one piece. The one before the cat came out relatively easily but the one beyond the cat was a stubborn b*&^%@#d; used lots and lots and lots and lots of WD40 and a fair pull on an open ended 22mm spanner. Word of caution, be very careful of the cables when unscrewing them as them soon become very twisted, unscrew slowly and test to see if it is free frequently.
The cat is definitely the cause of the rough running, bits are falling out and you can hear something large rattling around.
The mounting studs(x4) from the manifold side look ok, should I replace them anyway????