Citroen Saxo problems. Should I get another automobile?

MK1 Saxo westcoast, 55,000 - common problem with outer CV joints and failing emissions. Think I should get another car or hang on a tiny longer?

What other cars would you suggest?

The CV joints should last for years, the CV joint boots should last the same (if they keep coming off then they have been incorrectly fitted, using cable ties for instance)

Emissions problems are also fairly easy to solve for anyone that knows their stuff. First step is to make sure it has been serviced recently with new air, fuel filters and fresh spark plugs. Next a good mechanic should use the emissions analyzer to determine what sort of combustion is occuring in the engine, and from that information should be able to diagnose what is wrong.

What are the emissions figures from your vehicle?

CO, CO2, HC, O2

EDIT:

Being lowered by 40mm will be putting extra strain on the cv joints as the suspension geometry has changed, with the outboard end of the joint being higher than before it is also being laterally pushed inwards, as the wheel drops the shaft becomes slightly longer, as it rises it becomes slightly shorter, if you try to visualize what happens to the shaft as the wheel rises and falls you’ll see what i mean.

The shafts are obviously designed to cope with this, but lowering the automobile by 40mm wasn't in the original design spec and it causes excessive wear, leading to a shorter lifespan.

I’ve seen that cat problem loads, it usually logs a fault code 'catalytic convertor ageing', fitting a citroen cat always cures it and fitting a cheap cat almost always causes it!

If your mechanic has not already done so i would advise fitting the original downpipe as well so that at least the exhaust is standard from the engine to the cat, this will increase back pressure and will probably improve the idle slightly, the fancy exhaust will not be producing any power gains anyway.

The erratic idle could be due to one of the temp sensors, either the coolant sensor or the inlet air temp sensor. The coolant sensor is either mounted in the side of the radiator or in the thermostat housing and the air temp sensor is mounted in the bottom of the throttle body, if you remove the inlet ducting and look into the throttle body you’ll see a little stub sticking in from the bottom, thats the temp sensor.

Both these sensors default to a value of -40C if they are disconnected.

So IF the erratic idle is caused because the engine ecu thinking things are warmer than they actually are then it wouldn’t be feeding enough fuel into the engine, but once the engine warms up and needs less fuel it runs ok. If this sounds good then you can try disconnecting these sensors one at a time, give the engine a moment to settle down and see if it runs any superior. Doing this is forcing the engine ecu to see a temp of -40, so it will increase the fuelling.

These sensors don't always simply fail, they often deteriorate slowly first. If you find it does help then replace the offending sensor.

If that doesn't help then you can try ruling out the possibility of an air problem, try opening the throttle butterfly ever so slightly by hand, if that cures it then drill a hole through the throttle butterfly.

The hole should be very small, about 1.5 mm, and it should be drilled slightly off centre to avoid the butterfly spindle but whislt still being a strong part of the butterfly. I know this sounds like a bit of a botch, but it has cured many problems, as the hole helps at idle, but anything over idle the hole is too small to affect the airflow calculations of the engine.

The third main possibility is trouble with the oxygen sensor, a possibility if the exhaust has been f****d around with. If you disconnect the O2 sensor then you will see it has 4 wires (you probably dont have 2 sensors, but if you do we’re looking at the first one after the engine[upstream]).

2 of these wires carry the signal from the actual sensor, the other 2 (pins 1 and 2 i think) are for the sensor heating elements, as these sensors only work at a temp of 350C or above. Using an ohmmeter measure the resistance across the 2 pins, if your reading is crazy then try the other 2 pins (there is the mad possibility i got the pins wrong! ).

The exact readings should be compared to a table using the long number printed on the side of the sensor body, but thats not going to be easy is it. All the readings on the table are low though, between 3 ohms and 12 ohms. anything significantly higher than this and the sensor is f****d. The other 2 pins of the sensor will never cause trouble no matter what anyone states (unless the wires are broken) as they work using the intrinsic properties of a metal whose name i forget, maybe germanium, which reacts by generating a voltage in the presence of oxygen when heated to over 350C. (i should know it as i studied chemistry at university!)