MOT Failure Lambda Probe Golf MK3 1998 1.6CL AEE

[Caesar]

DearAll

My Golf Mark 3 1998 Reg AEE enginee code has today failed it MOT Test due as the tester said to emmissions. He said the most likely culprit was the Lambda probe. PLease advise if this is the most likely problem or could the problem lie elsewheer and also how easy is it to fit this probe? many thanks in advance for any help.

 

[davieboy]

can you post the emmissions readings from the printout you will have received

ie, HC, CO, CO2, O2 and Lambda.

many things can cause an emmissions fail.

 

[^neo^]

Clean the throttle body, chuck a new air filter in, and make sure the oil breathers aren't gunked up with oil/crud too.

What does it start like in the mornings?

 

[Caesar]

HI Davieboy

The test results are as follows:-

Fast Idel Test fail

CO Level 2752RPM = 10.57% FAIL

HC Level 2752RPM = 376 ppm FAIL

Lamda 2752RPM = 0.72 Fail Min 0.97 Max 1.03

Second fast Idle Test

CO Level 2643RPM = 10.97% FAIL

HC Level 2643RPM = 408 ppm FAIL

Lamda 2643RPM = 0.72 Fail Min 0.97 Max 1.03

Natural Idle Test fail

Engine Speed = 675 RPM Pass

CO Level at 675 RPM = 11.86% Fail


I have had a new Lambda probe installed and the CO went down to 5.54%
The probe registed 0.87 instead of min of 0.97 although it was taken to the MOT station straight after the Lambda was fitted and fitters checked on thier emissions machine and it passed!!!!

BUT STILLL FAILED THE MOT when taken to original testing station!!!!

Any Ideas? many Thanks

 

[Belle427]

http://www.omitec.com/en/support/tech-tips-gen/gas-analyzer/

have a look here to help you with the readings but start with the basics first as mentioned such as the air filter,plugs etc

 

[Caesar]

HI Neo

Starting in the morning is fine. Maybe the Lambda probe installers put the worng probe type in?

 

[Agile]

Unlikely!

When was the air filter last changed?

It sounds to me to be that kind of problem!

Its not an obvious culprit but sometimes an old fuel filter ( if yours has one ) can give unexpected results.

Tony

 

[Caesar]

Hi All

The Air Filter inlet and bofdy was cleaned thoroughly with Carb Cleaner and some was sprayed into the trottle housing i.e past the butterfly whilst the engine revs were very high in order to shift any gunk on the injectors etc after about 5 mins an Eggy smell appeared and after some twenty minutes it disappeared! The car was then tested as a trial on an MOT Emmission tester abd the chap there said now even the CAT has failed!

When I drove back whilst a new was ordered the car lacked power abd was very hesitatnt whilst cold but soon returned to normal once the engine temp reached normal!!

Any more ideas folks as this has got me stumped! The fuel filter has never been changed though!

 

[Agile]

The CAT is after the engine and so the only effect it has is on the emissions and to a small extent perhaps on the reading given by the sensor assuming thats after the CAT near the end of the exhaust. The sensor would then alter the operating parameters but thats more fine tuning rather than big changes.

As far as I am aware CATs dont "suddenly fail" ( unless they are dosed with leaded petrol! ).

You have not actually said that you have changed the air filter! I presume that you have???

Diesel injectors inject directly into the cylinder and are subject to fouling and putting additives in the fuel is often required to clean them.

I think that all ( or at least most ) petrol injectors are into the inlet port rather than directly into the cylinders and so their operating environment is a lot easier. Just possibly an additive in the fuel would help but I doubt it.

I cannot pinpoint exactly what is the problem but it seems that they are panicking and wanting to change part by part until they get the right one.

Its a pity car people dont offer a no-fix no-fee as I do with gas boilers.

Tony

 

[Caesar]

The Filter is fairly new and was not replaced. The tester even tested the emissions without the filter / body installed but again car failed emmissions! The NEW Lamda failed as well as its range should be between 0.97 and 1.03. The Lambda reading was 0.86! so after the tester changed 3 lambda probes the emmissions still failed. On the last test it as I have said failed the CAT as well.

 

[Agile]

The sensor READING should be between those figures BECAUSE the exhaust gas composition should have a certain composition.

You need to adjust the combustion characteristics, not replace the sensor !

If a carpenter changed his tape measure whenever a piece of wood was too long.....

Tony

 

[^neo^]

Where in London are you?
If you're south side, let me know and you can bring your car down and plug it into VAG-Com and see what is going on.

 

[Agile]

Wow.. someone nice to know!

Still worth driving across london to someone who knows what they are doing!

Tony

 

[Caesar]

Dear Neo

Many thaks for your kind offer and I may take you up on it! Although I don't live on the south side of London I live in the North West London at Ruilsip. Let me know your address just inb case! The Garage is now thinking of replacinig the lambda Probe with an original VW one! They will also replace the CAT at trade price!

The Generic Lambda probe they fitted now makes the car run very erratic! It kangaroo jumps , cuts out at low speeed, hesitate to accelerate and does not idel evenly till at least when the engine is at normal running temperature!!!!

The Air Filter has been replaced along with the spark plugs and fuel injector (WYNN's) has also been added.

 

[^neo^]

can't do emails and things on this site, so pm me on gsfcarparts.co.uk or clubgti.co.uk

Sounds like you need another garage in all honesty, and preferably someone who knows dubs!