Xsara VTS and Catalytic Converter/Oxygen Sensor

[DJ-Studd]

Hi guys.
A few quickies-
a) How easy is it to check for a faulty catalytic converter and/or oxygen sensor?
b) How easy is it to fit replacements
c) How much should I expect to be set back for replacements? If replacing, are there alternative "performance" versions?

Ta.
-- DJ


Edit: The car has, for a long time, been spitting black "stuff" out the exhaust and onto the rear bumper. Lance Dixon Citroen said this was due to the intake manifold and performed a cleaning ritual on it. The car is still doing it, however Thoughts? It's out of warranty now, but has been doing it for most of the warranty period.

Edit 2: Car (not engine) often runs "rough" at idle, as if an exhaust mount is broken - lance dixon said they checked the exhaust mounts and they were fine. Thoughts? Occasionally when I plant the foot, the car feels like it can't breathe, resulting in a not-so-fast accelleration...

-- DJ

 

[O'Murchu]

I had the oxygen sensor replaced under warranty about eight months ago. It's been fine ever since. No idea what costs are involved on the non-warranty side. Probably astronomical(that wasn't very helpful, was it?).
As for the "black stuff", it's common to lots of cars/engines. Just normal exhaust release. The outlet on the VTS is set very close to the body, so you're more likely to get the build-up. Would be helped by not pushing the engine when it's cold.

regards,
Keith

p.s. Sluggish takeoff and poor idling?.Sounds like you need a tune-up big fella!

 

[danielsydney]

Hi

My o2 sensor went on my old Renault 19 and the cost was about the $150 mark from memory....

 

[Fordman]

From a mechanic's point of view (not Citroenised):

The last things I would be looking at would be the cat or the oxy sensor - until diagnosis of the problem was carried out (but I wouldn't rule anything out).

The oxy sensor either works or it doesnt - and you would probably have more serious problems of (very) high fuel consumption and smoking exhaust etc (over rich mixture). It can be tested. If you like fiddling, fit an air/fuel ratio gauge and watch what the oxy sensor is doing (Auto Meter brand - Super Cheap Autos can supply. http://www.autometer.com/ ). It will cost you as much as an oxy sensor, but much better fun.

The cat converter would probably give low power all the time, not just occasionally. It would continue to get worse over a period of time. The couple that I have seen actually fail have happened fairly quickly - going ok one day - a week later wont even run above idle. Its pretty rare.

As far as a tune-up goes, other than replacing sparkplugs and keeping leads clean, theres not much you can do. Your plugs are probably platinum? which should last 50 - 100k kms if the correct plugs are fitted. This is presuming that it is a fairly late model with engine management system. The plugs are fairly expensive so you dont replace them willy-nilly. If it actually "misses" then the coil packs are the first suspects.

As has been said above, the black spots from the exhaust are pretty normal, especially if you are doing mostly short runs and it never gets really hot to burn the crap out of the exhaust. Even then the condensation in the exhaust from parking overnight will spatter watery black muck the next morning. As long as you aren't losing coolant with a faulty head gasket or something.

It is also normal for the engine to be slow accelerating until it warms right up. This is designed into the EMS to stop the engine being flogged when cold. However if the temp sensor is dicky it may cause this to happen at other times. But there are many things to look at and a good diagnosis should pick up on the problem.

What I am really saying is - until you've got a real problem, it may be a bit hard to diagnose, and it may be better to leave it for a while and see if the "problem" develops. Until then I wouldn't be spending too much on it.

That's my 2 bobs worth - others may disagree.

Cheers
Fordman.

 

[danielsydney]

I agree with fordman i think on this one......If your in sydney take it to continentals mate.