Failed the MOT today on emissions, spectacularly.

I mean big time. :lol:

5.52% fast idle compared CO compared to max of 0.30%, 2nd fast idle of 4.21% compared to 0.30%, and natural idle of 1.50% compared to max 0.50. Oh and to top it all off, failed the HC section too. :lol:

Lambda sensor I'd imagine.... MOT tester couldnt remember if there was 1 or 2 on this model, any ideas?

I dont know what engine 'type' it is, unless anyone can point me to something that'd tell me easily.... Engine number ends in AME? that the one?

Where is the damn sensor to begin, how easy/quick a job is it to replace it, and any other suggestions to make it get through the MOT?

Its idling and driving very slowly and sluggishly, just want to get a ticket on it to get shot of it and get a better one.

thanks.

There are 2 sensors, though don't condemn any of them without getting it read for fault codes. Dirty air filter, dirty throttle body, faulty temperature sensor, broken thermostat, dirty fuel injectors - any of these can contribute to an emissions failure.

Ive just had alook at my emissions sheet from last years MOT , I have the same car but the values are different to the ones you quoted , have they changed at all does anyone know? On the fast idle test it quotes the permitted maximum CO % vol as being 0.200% (actual figure from my car last year was 0.029%) , and the natural idle test quotes a max CO % of 0.300% (actual tested value 0.011%). Also they only done one fast idle test , is the 2nd one ommitted if the car passes the 1st one?

Most likely the 2nd one is omitted, yeah.

I'm going to throw a new lambda in there, see if that helps, otherwise I'm stuffed and might have to try a new cat. Well one from a breakers, at least.

As mentioned why not find out what is causing the problem rather than just throw money at it. If could be a faulty temp sensor.

VagCom'd the car, came up with:

3 Faults Found:

16725 - Camshaft Position Sensor (G40): Implausible Signal

P0341 - 35-10 - - - Intermittent

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

P1116 - 35-00 - -

16502 - Engine Coolant Temp. Sensor (G62): Signal too High

P0118 - 35-10 - - - Intermittent

So will replace the temp sensor, possibly lambda, then look at the CPS..

With regards to the Lambda, any idea's if the 1.4 has 2 sensors, and if so which one is the one that the fault code is telling me about?

Thanks!

It is the first lambda sensor, before the catalyst. Replace this and as the other faults are intermittent just clear them and check again at a later date to see if they have returned.

Hello All Sorry for jumping in on your tread, my wife has a 8v 1.4 mpi and has two faults on it P;0170 Fuel Trim malfunction bank 1 and p0139 lambda sensor B1 S2 response to slow.Can any one point me in the right direction i was thinking changing lamda but i dont know is this pre cat or post cat as i dont want to change the wrong one. I checked the usaul for vac leaks found one perished pipe which i replaced but still the same clear but returns within a day or two. All other fuctions pass on readyness test fails on cat and o2 sensor.

B1 S2 (Bank 1, Sensor 2) is post cat, as it is showing a fault it would be a good place to start. Once replaced it may be worth erasing the learned values in the engine ECU, 01 engine, 10 adaptation, channel 00.

thanks ford fan will have a look cheers, you up early fixing the worlds problems!!! i dont have a vag com thing but have a vag 409 reader no live data ah well.