Xantia 1.8 16v 1999 MOT: Emissions falure

[Citronight2]

Hi all,
I need some help to find out which component fail on my Xantia 1.8 16v, MAP,-- MAF, - or OXYGEN sensor?
The CAT has been changed a few years ago, hope its not that
Has anyone "near" Brighton got a lexia for testing what's causing the failure.

Thank you

[myglaren]

There is a list of members offering diagnostic help here.
At the bottom of the page is a link to a map of approximately where they reside.
If there is a suitable one for you, click on the link that is their name which will take you to a page with their details on and a contact button where you can send them a PM and arrange a diagnostic session. Check also when they were last active as they may have stopped visiting the forum.
Note that it is all voluntary and not everyone logs in here all the time so a response can take a while.

[Citronight2]

Ok Myglaren,
I message one of them from the list, hope I`ll have a response.
THANK YOU )

[Stickyfinger]

IF the replacement was an After-Market item, the that could be its life, they are well know for not being good on Citroens of the Xantia/Saxo age group.

I struggled to get my SAXO past emissions....it needed to get very well run up to temp (HOT/Have its Nuts rev'd off for ages) to pass... I know Xantia v.6 & 2ltrs have the same problem. OEM are big old school CATs and the much smaller new types do not seem to work as well at "normal" temps for these engines.

It is well worth checking the intake system for leaks, little splits are hard to see but can really screw up emissions as they pull a lot of air when under vacuum.

[peter306]

Hello, My 1.8 16 valve xantia fails emissions every two or three years, as Alasdair says aftermarket cats don't have the same life. I change mine every three years (or sooner). Only other reason it failed emissions the O2 reading was all over the place, the O2 sensor had failed but if you're getting a steady but too high reading then probably the cat.

Peter

[CitroJim]

The reason you so often need to rev the balls off the engine and get it really hot is the cat is located a long way (by modern standards) from the exhaust manifold and thus the exhaust gasses have a chance to cool before they reach the cat... These modern ones, intended to dangle off the exhaust manifold, really don't work well in what is a sub-optimal location for them.

I sometimes wonder if a bit of lagging on the manifold to the cat downpipe and indeed around the cat might help? The sort of stuff you see on racing tubular manifolds.

Never a problem on the old-school cats, which generally were about three times the size and weighted a ton. The V6 Xantia OE cat is huge and is almost a two-person lift!