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minijet
I've just acquired a replacement front pipe (cat), and I'm going to have it fitted at the local garage.
When they had a look under the car I got the impression that they were expecting to have to fit a new lambda sensor.

Does a new one need to be fitted, or can the old one be refitted?

Do they damage easily on removal, is there a special way to remove it?

If a new one does need to be fitted, do you snip the old wires and patch the new wires in to them, or is it better to feed the new wire all the way up to the connector........somewhere in the engine bay I think?

Also, I need a new fitting kit - 1 clamp, and the two long bolts that have the springs and washers round them, and the nuts of course - the old ones are rusted up and will probably have to be cut off.
Does anyone know where I can get them? Citroen don't do them.

Thanks,

Paul.
Andmcit
The fitting kit is available from GSF for around £15 and worth buying; IIRC it includes the
wirewool donut so overall not a bad purchase in the scheme of things.

I'd rely on the original connection as splices aren't a great addition in the engine bay if you can
help it! The connection is near the LHM reservoir on my V6.

I'd certainly try undoing the sensor with a ring spanner fed over the wiring first and see if it does
come undone. On the 2.0i I recall the sensor lives directly above the main cat box so access may
be totally dire! Helped replace the main downpipe on my BIL's 1996 Pug 306 that has a lambda
on the start of the pipe and it undid without drama and happily works on the new section of pipe
so no reason the slightly older XM can't be any different! biggrin.gif

Andrew
minijet
Thanks Andrew,

where/what does the wire wool donut do?


I just got round to having a look at the replacement exhaust, and to be honest it doesn't look any diferent to the one that's on the car.


This is the one on the car, it's the area around the joint that's damaged.......allegedly.

user posted image

user posted image

It's certainly blowing around the joint, but I can't see where the damage is.......(apart from a little chip out of the flange).

I'm not sure that the pipe is damaged at all.
It looks to me like the clamp has been displaced and just needs repositioning.


This is the replacement one, I couldn't get the same view as the one on the car as it has a protective plate fitted to the underside of it.
The one on the car should have it but it must have been knocked off when the car grounded on a bump.

user posted image



I may have bought another pipe for nothing.......I'm glad it wasn't a new one.

Does anyone have a picture of how it should look please?

Should there be anything besides the clamp?.....a seal or anything?

Thanks,

Paul.
dean
Hi minijet

It looks like the exhaust has taken an impact, and seperated at the joint between the down pipe/cat and the middle section.
The plugs for the labda sensor are under the LHM tank, one red and one white plug both two pin, one is the feed and earth for the heated tip and the other for the signal to the ecu, if you get an aftermarket labda probe they dont come with connectors on and you will have to cut and join the wires the cit one is near £200 and will plug strait in but you dont have to change it so long as you can get it undone from the old downpipe.
There should be nothing but the clamp for the joint in question but if the mating surfaces are rusty i would join them with something like bossal exhaust sealer..its good stuff wink.gif
The wire donut seals between the manifold and the downpipe/cat.

D
Andmcit
As you say, the flange on the cat fitted has part of its lip broken away and doesnt look very good
with the collar bracket not making a seal. Unless you replace or repair this chip on the flange the
overlap will be challenging to seal.

Basically, no sealing putty/paste must be used upriver from the cat and this explains the use of the
dense wire wool type donut I mentioned as it acts as a natural compressed seal from the manifold
to the downpipe. After last years batch of dodgy fuel at garages in the south east, a lot of lambda
sensors were advertised on ebay and mainly sat somewhere between 30 to 80 quid. The socket size
diameter is quite large but the thread is shallow and likely to rust and break up - bad news for
reusing a cat but potentially ok for the sensor - obviously it needs to be air tight so it needs good
thread!

I'm on my mobile so the pictures you've posted are taking a while to load; does the replacement cat
have a sensor fitted or just a threaded opening?

Andrew
minijet

Thanks Dean,

I'm hoping I can get away with simply refastening the joint.

I wish I'd looked at it myself instead of leaving it to the mechanic, he said the pipe was actually broken at the joint and I needed a new one, but I don't see it.

I'll have to get the clamp off and have a better look, hopefully I won't have to touch the lambda sensor at all, and I can save the other down pipe for another day.

Thanks again,

Paul.


minijet
Andrew,

The joint is 'downriver/downflow' from the cat, so presumably it's ok to use sealing paste/putt etc, but I take your point about repairing the chip in the flange.

The replacement cat doesn't have a lambda sensor fitted, just a threaded hole.

Someone is selling a cheap replacement lambda sensor on ebay.......

http://cgi.ebay.co.uk/NEW-4-wire-Oxygen-o2...Q2em118Q2el1247

..............................but I need to check the wires to see if it's the right sort

Thanks again,

Paul.
dean
The 4 wire ones are most common so i think you should be ok there but check first obviously, your right about the joint though if you can repair the chip it will go straight back together, even with the chip and some sealant you could be ok but its hard to tell until you get it apart.
Just noticed the stones stuck in the underseal, have you been off roading in it? laugh.gif

Good luck with it Paul

D
minijet
QUOTE (dean @ Dec 19 2008, 17:08 PM)

Just noticed the stones stuck in the underseal, have you been off roading in it? laugh.gif



I bebbledashed it for extra protection......... tongue.gif


Thanks Dean.


Paul.

dean
laugh.gif i like it, NEW ANTI-SLIP WAXOIL UNDERBODY SEAL;)

D
Andmcit
Hang on: the trade off with better rust protection is more wind resistance as it cleaves through the
air!!? Then there's the additional weight ballast you're carrying! Maybe why you're disappointed with
the fuel economy...

Maybe it needs waxing and removal of these extras!? wink.gif

Who said Brazillian? tongue.gif laugh.gif
God it's so good to be back on Club-Xm! Xmas came early when it looked out for the count...

Andrew
minijet
QUOTE (Andmcit @ Dec 19 2008, 18:05 PM)
Hang on: the trade off with better rust protection is more wind resistance as it cleaves through the
air!!? Then there's the additional weight ballast you're carrying! Maybe why you're disappointed with
the fuel economy...

Maybe it needs waxing and removal of these extras!? wink.gif

Who said Brazillian? tongue.gif laugh.gif
God it's so good to be back on Club-Xm! Xmas came early when it looked out for the count...

Andrew


Next time I'll go for a plain face sand/cement render for better streamlining tongue.gif



I like what you did there Andrew........XMas.........that's good tongue.gif


Mery XMas everyone

DerekW
I've just logged on and read this thread. Another wealth of good information and I've got an ear-to-ear grin that'll see me through Christmas.

Derek
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