960 exhaust change

[bumble]

Please help guys - I have always run a 740 or 940 estate with red block.

Now Im running a '95 facelift 3.0 960 saloon which is giving me no end of bother.

Just had the exhaust changed - full system which was not cheap. After I picked it up I got 1 mile down the road and then it went to 'limp home mode', would rev and the ac off surround red light was flashing but not the emission warning light on the dash. Turned the engine off and then on starting again it went back to normal but the exhaust was blowing like a motorboat so I took it back to the guy who fitted it and he said that the fit between the cat and mid section wasn't clamped well enough.

Drove it for 1 journey, left it overnight and then it started very lumpy and the emission light on the dash came on. It now runs fine but the emission light is on all the time. I went back to the exhaust guy who said 'nothing to do with me guv' etc etc and that he reconed that a new exhaust and the sensor'doesn't like it'.

Thinking it was the lambda sensor in the exhaust I got underneith to have a good look. It looks like there are 2!! 1 before and one after the cat. Also they look like rather than being on a plug the wire is attached and then goes off to the front of the car.

Questions:
Is running it with the emission light on going to be a problem?
Can I live without 2 sensors?
Where does the wire terminate?
Is it a hard job to change?
Will an OBD2 test tell which one is faulty or could it be anything else?
Is it likely that my **** mechanic broke it and if so how?
If that is the case could it just be 'refitted' incorrectly and an easy fix possible?

Please help cos I spent my last cash on the exhaust and I wish I hadn't touched it now.

[bumble]

There's more -

The original tail pipe has been welded onto the new back box.

I put this as a question to the bum mechanic who fitted it who said that it was definately the correct box but that the pipe didn't fit - ie protude out of the cut away in the bumper - and looking at the part he cut off it looks exactly like a 940 back box with a sustancial s shape to the pipe.

Could this be the wrong box and could this be causing an emmision fault on working sensors??

[Chesh740R]

Sounds like he's fitted a 940 exhaust or an early non facelift 960 exhaust to your facelifted 960.

The below link should show the 4 differing types and the **** up he has done.

http://www.catalogue.bosal.com/pages...olvo&model=960

If yours is a 3.0 Facelifted then it should have the 4th system listed on that page made up of parts

278-193 front pipe http://www.ebay.co.uk/itm/New-Bosal-...item2c6c353a3e £65 on ebay
235-193 Back box http://www.ebay.co.uk/itm/END-SILENC...-/380570544693 £100 on ebay

So £165 plus fitting.

If he has welded the exhaust on the car, then he could have fried your O2 sensors/ possibly at worst the ecu causing the rough running.

I'd print out the bosal catalogue i linked above, compare to other parts, take it back to him threaten with trading standards or court costs and see where he goes then.

[bumble]

He's not a pro and he does alot of other work for me so I can't be nailing him for being poor - basically the work done cost me nothing in exchange for some other work.

Yep - he has fitted a pre face lift back box and than hammed the tailpipe to fit at the end.

Would/could this cause an emission warning as the lambda sensors are on the 1st section before and after the cat which is a genuine correct volvo part as I provided that? Im guessing there is no sensors in any other part of the exhaust..... there is a damn sensor in everything - this is my 760turbo all over!

Note to self and anyone buying another volvo - get a redblock!

[Chesh740R]

The front pipe has a pre and post cat 02 sensors. If these were replaced i would check that they were plugged in properly.

The only other thing to do is get the codes read to see what faults are showing.

[bumble]

Thanks -

Do the sensors need to earth around their bases similar to temp and oil sensors which I have known to fail due to poor seating?

The sensors are in the holes - as it were - and both look like the correct way round. Aso would that acoount for the way the emmision light came on, that is not during the 1st drive while the cat was still hot but the next day when it needed to warm up again??

As I asked before - is it possible to damage the sensors just through a change of exhaust.... I mean they just look like a knuckle with no moving bits?

[Chesh740R]

Nope you shouldn't damage o2 sensors just by changing the exhaust, but if he was perhaps brutal and stretched the wires it could have broken them.

02 sensors can fail at anytime, maybe you've been unlucky, but also if he welded the exhaust whilst it was on the car, then i have read that it can damage 02 sensors.

You need to get the codes read, and see which codes its throwing, it will either show pre cat or post cat sensor is playing up or it could be something else.

[bumble]

Thanks Chesh for your input.

Codes are P0130 and P0135 which would be precat o2 heater and sensor circuit... OBD2 is cool iniit

Interesting as I noted before, this issue has occured after the exhaust has been changed so next job is to get underneath and have a look, see if the sensor or wireing has been damaged.

Asking motor mates - non volvo dudes - some have experience of this as a 'refered fault' caused by the failure of something else which is concerning but.... as the exhaust has been messed with....

Setting this senario out to a friend he thought that if the exhaust had not sealed at the joint and it had been run with a hole in it - of sorts - could cause the heater in the sensor to 'burn out'. Can anyone on the forum confirm that as possible??

Also does anyone else on here have any experience of this fault? Any things to look out for? Im wading in untrodded water with this one!

Ill keep you posted with progress.

[740T]

Have you disconnected the battery since having it fitted? When I got my system on the 740 the car was running very rich. Disconnected the battery left it for 5mins and reconnected. All back to normal.

[GrandadRob]

I have a facelift 2.9 1996 estate. Ordered backbox from Eurocarparts.com via their website. They sent the long tailpipe version, when I queried it, they were adamant that there was ONLY ONE SORT. I have informed them of their error and am awaiting a reply.
So even the so called professionals get it wrong....................