Diagbox Issues

[mrtee]

Hi, my car (xsaraVTS) recently failed its French Mot on emissions. I have been advised on another forum I need access to the live data to help solve the issue.

 

After a lot of messing around I have got a version of Diagbox installed and connected to the car. The issue now is that the software options coming up don't seem correct. By this I mean there is no obvious options anywhere to access the live data like I need to  and after watching some youtube videos the version I have (which should be fine) is nowhere near like the videos as to the amount of funcionality.

 

Please see the screen shots below, am I missing something????

 

 

[paul.h]

Welcome to the forum.

 

I can not help with diagbox having never used it although your first picture has Parameter measurements and maybe that has something. EOBD was not required before 2001 for a petrol car so is the diagbox communicating with your car.

 

I guess your car is a petrol and provided it has up to date servicing (air filter, spark plugs, no air leaks, oil level ok, it is warming up ok without a temperature sensor fault) then the problem may be a faulty lambda sensor before the catalyst (upstream) or a faulty catalyst. If you can get live data then check the coolant temperature is about 95°C (the radiator top hose shold be hot), the upstream lambda sensor should be switching about and the downstream lambda sensor after the catalyst should be steady. If the upstream sensor is not switching then it may be faulty. If the downstream sensor is not steady then the catalyst may be faulty. However, you have not mentioned the engine fault light coming on and any fault codes which may be given if these were faulty.

[mrtee]

Hi thanks for the reply. Cat is fairly recent and servicing is all good. Here is the reading info:

 

The reading is as follows:

 

C0 Ral 1.12

C0 Acc 3.08 

Lambda 0.910

 

 

 

Thanks.

[paul.h]

In the UK the emisions limits from the MOT testers manual for cars from 1/9/2002 are

 

- fast idle test 2500 to 3000 rpm

CO <= 0.2%

HC <= 200ppm

lambda 0.97 to 1.03

 

- idle 450 to 1500 rpm

CO <= 0.3%

 

So it appears your car is running rich. If the catalyst is still in good condition then maybe the upstream lambda sensor is faulty but it would help to confirm this with live data. Also check the throttle body/plate is clean and not bunged up with carbon/oil. If you do replace the lambda sensor it may be better to get the right one from a dealer since sometimes generic ones may not work as well.

[coastline taxis]

what are the emmision limits in france. And yes go for paramiter measurments although i cant see how it will help you as it dosnt show what is coming out of the exhaust. What year/engine is in yours

[mrtee]

I believe the limits in France are the same as the UK.  The car is a 2001 Xsara VTS 2.0 petrol 167bhp (same engine as peugeot GTI-6).

 

How do I check the throttle body/plate? Thanks.

[mrtee]

Forgot to add - car is running fine and average mpg is the same as always.

[mrtee]

I have got some screenshots from the software with the engine at different RPMs, I guess this is hte live data I need? Let me know if this throws any light on the potential cause of the emissions issue, thanks.

 

 

 

 

 

 

Edited September 5, 2014 by mrtee

[paul.h]

The one thing that stands out is the coolant temperature is only 74 to 80°C. Unless the engine has just been started this means the thermostat is faulty so the engine is not heating up and will be running rich. It should be about 95°C once warmed up. If it does warm up fully then you need to look at values then. I do not know how the oxygen sensor (lambda sensor) voltages relate to lambda values but until the engine is warm the values shown probably do not mean anything.

[mrtee]

ok will try again with the engine warm, it hadnt been idling for long.