Lambda sensor - where the hell is it?

[dss123]

Quick question to all the technical bods.

Where is the Lambda sensor on the S1 (111S)

My car failed it's MOT on emissions (high Lambda reading), so bought a new sensor with the aim of fitting it last night.

Couldn't find the damn thing for looking! Took the boot lid off and thought I could spy some heat proof ducting way down by the manifold, by the joint to the rest of the exhaust system. Just couldn't reach it though - is that where it is?

Any advice on how to reach it gratefully recieved.

My next thought was to try from underneath?

Am I looking in the right place?



Cheers



Dunc

[fergusd]

It's on the rear face of the 4-2 part of the manifold (the top part), very close to the join to the downpipe.

Fd

[dss123]

Mmm thanks FD - where I thought.

Is it best reached from the underside with rear undertray and diffuser removed?

Dunc

[adrianr]

Yes, but be warned that 'Lamba sensor' is the MOT monkey's stock answer for all emissions related problems.

Before you discover what a b***h it is to swap the Lambda sensor, just make sure the rest of the exhaust is in good nick - any loose joints that let air in or exhaust out will probably have the same effect on your emissions.

In particular, make sure the exhaust manifold mounting studs are still present (they rattle loose) and that the flexi-section hasn't given up.

AdrianR

[dss123]

Thanks guys but it's too late - already spent a few our trying to remove the bastard - resorted to hacking the bulk of the sensor off and gonna have a try with a socket at the weekend.

In actual fact - the MOT guy didn't really offer any possible cause to the failure apart from exhaust leak. I thought the Lambda was the most likely reason. CO2 and HC fine, poor fuel economy recently etc etc.

I really hope it is the reason, hate to have gone through all this for nothing!