Can anyone shed some light on this?

I took my99 2000 turbo wagon for test yesterday and it failed on the Gas test. I have a standard exhaust to just beyond the middle and then I have a H&S backbox. The results of the test are as follows;

Fast idle Test
Engine speed ---rpm
CO Level 1.28% FAIL
HC Level 15 ppm PASS
Lambda 0.97 PASS

Second Fast Idle Test
Engine speed ---rpm
CO Level 6.31 %
HC Level 100 ppm
Lambda 0.83% pass

Natural Idle test
Engine speed ---rpm
CO level 0.71%

Will I need to change the Lambda, The CAT or both. Could there be something else that is causing the problem?

 

so no cats have been removed no? Id be inclined to go back and ask for the gas test to be done again, but take it for a good thrash before hand, so that the engine and cats are both really hot.

 

I had the same problem last year

Had to get both Lambda sensors changed at a cost of £600 odd quid ncluding new brake pads.

Unfortunately due to bad weather i could only get the MOT on the day it expired so had to get the work done

Was most annoyed but that will teach me for leaving it so late.

 

Hi i agree with Andy get the car really warm and try again where r u based have you any problems with hesitation or high fuel comsumption if not a good blast might do it.

 

Thanks for your responses. I have heard that a damn good heating on the CAT should work however the MOT station were of the opinion though that the levels were exceptionally high and was probably not due to a cold CAT. My oil was measured at 80 degrees, which is the minimum for the test, does anyone know what their oil temperature was when the they had their test done?

Winker,

I am in Weston-super-Mare. I have had a suggestion for where I may be able to get a test done, ( )but would like to know if there was a genuine problem.

Does anyone think these levels are exceptionally high?

 

Thats right the CATs are still on the car

 

We dont test the oil temp at my garage, but if we ever struggle getting a car through on the emissions, then we usually hold the revs up to about 2500RPM for a few mins and nine times out of ten you will see the levels go down into the green, then we do the test again and it will usually then go through.

 

Lambdasensor is defect

 

I agree.

The Lambda reading for second test looks way out and I can't believe that it is a pass at 0.87 ?? I thought that the limit was 0.97 - 1.03 for a pass. I'm not sure what the % sign is for after the Lambda reading , is it just a typo as Lambda doesnt have any units, its just a ratio.

Could you check the numbers ??

 

Yes the % is a typo as is the pass after it. I should be more careful with my copy and pasting.

 

OK, in that case I would definately suspect the lambda sensor, if its not keeping air/fuel mix = 1 then the cat doesnt get a chance to work properly. The results from the first test show that when lambda is closer to = 1 then the HC are nice and low, so the cat is working OK when the lambda is right.

 

Just to let you know, new Lambda and plugs fitted. Got it nice and hot on the way and when I got there did the old remove a spark plug lead trick and she passed with flying colours.

A big thank you to you all for your help.

 

yeah the secret is getting them really hot like almost thrash the yakes of the car and then pull in to do test straight away it's rubbish i know

 

remove a lead, so its running on 3 cylinders?

 

does that work?

 

run it low on petrol and squirt a bottle of redex in ur tank...helped get my smokey jeep through...

 

Yes remove one lead

It certainly does. See the link below.

http://www.scoobypedia.co.uk/index.p...tMotFailureFix

 

arr i was thinking, by removing the lead, it would show less co2. so was think it would of worked with a decat