Hey guys-any help will be greatly appreciated!!

2003 Octavia VRS went for MOT today!! It failed on Emissions by a huge amount!!!

So i dug out last years results to compare. The results are as follows:

Last Year This Year

Fast Idle: Engine Speed Limit Actual Engine Speed Limit Actual Second Test-This Year

2500-3000rpm Pass 2350-2650 RPM Pass Pass

CO2 <=0.200% 0.082% CO2 <=0.300% 3.739% FAIL 4.185% FAIL

HC <= 200 PPM 32PPM HC <= 200PPM 107PPM PASS 133PPM PASS

Lamba 0.970-1.030 0.015 Lambda 0.970-1.030 0.909 FAIL 0.887 FAIL

Neutral Idle: Engine Speed

450-1500 RPM Pass 710-1010 RPM Pass

CO2 <=0.300% 0.002% CO2 <=0.500% 3.018%

That is a huge jump!!

Does anyone know what could be causing the difference??

Please Help....I love my car and miss it!!

Thanks in advance

Lamba 0.970-1.030 0.015 Lambda 0.970-1.030 0.909 FAIL 0.887 FAIL Huge hint here in the way out of spec Lambda values! Has your car been heavier on fuel recently?

Lamba 0.970-1.030 0.015 Lambda 0.970-1.030 0.909 FAIL 0.887 FAIL Huge hint here in the way out of spec Lambda values! Has your car been heavier on fuel recently?

A little heavier on fule than usual.

I guess what Ken's telling you is that you need one of these:

http://cgi.ebay.co.uk/AUDI-TT-1-8-SEAT-SKODA-OCTAVIA-VW-GOLF-LAMBDA-SENSOR-/190455957924

(Might be the rear one - a fault code scan should tell you which...)

Hey guys, thanks for your help so far!!

So i got code reader on it and it brought up 2 codes they are:

17511-O2 Sensor circuit heating circuit (B1-S1)-Output too low

17524- which is not in the book

So i have looked under the car and i have 2 lamda sensors on the exhaust. One is nearer the front of the exhaust and one which appears to go into the centre of the cat.

Anyone know which sensor it is that needs changing???

And if not, if i change one and the problem persists will i be able to put the one i took out back in and put the new one in the other one, ie are they the same fittings etc??? (I hope that makes some sense!!)

I can afford to replace both at the mo but need my car back to health!!

Thanks again for ll your help guys!!

b1 s1 is the pre cat sensor (the one before the cat)

the 17524 doesnt show on ross tech either?

17524 - Oxygen (Lambda) Sensor Heating: B1 S1: Open Circuit

Thanks guys for all your replies!!

I will try that then and update you.

Hey guys, sorry to keep on about this (I never knew it would be so difficult!!)

_

So we bought the lambda sensor and we asked for the pre-cat one. got the car the ramps and set to work, only to find that they had givenus the sensor that goes into the cat!! (post cat)

Also this may sound like a daft question but i have been looking at the 2 sensors on the exhaust underneath the car, they are fairly close together in the haynes manual they are labelled as upstream oxygen sensor (pre cat) and downstream oxygen sensor (Post cat)....are these the correct ones to be looking at?? or should i looking elsewhere??

Also all the ones on ebay seem to have only 4 wires but my pre cat sensor has 5 wires (coloured). My rear sensor is the one with 4 wires(black and white).

So we rang the place we got the part and they only list post cat sensors!! and apparently we can only get the pre cat sensor from a skoda dealer!! surely this is not true??

Could anyone point in the direction of somewhere the get the right sensor please?? somewhere in Leicestershire would be nice so i can get it quicker!!

Thanks again peeps

Edited 14 December, 201015 yr by Tavie

5 wires wide band on the front mate think gsf do them for about 60 pounds

5 wire probe

Perhaps it's this one you need?

Hooray!!! I have a legal car again!!!!

Thanks for everyones help!! I can not believe how easy it was to change the sensor it took 20mins and that included waiting for the exhaust to cool!!

We eventually got the sensor for Macpac as GSF did not have any, thanks danp for the tip.

I have reset the engine management light and it has not come back on!! My lambda readings have dropped significantly (Although i think the engine is still adjusting itself)

THanks to everyone again