Lambda sensors and 4-2-1?

[Dave-R]

My Pug must have known I was changing the manifold soon for a 4-2-1 Supersprint because the OE manifold has a nice hole in it where the lambda should be (rusted around the lambda and broken off).

My car has the cat in the manifold and two lambda sensors. I'm assuming both of them are lambda sensors? Can anyone shed any more light on this? Is one an O2 sensor and one a CO2 sensor?

I've got myself a lambda sleeve ready for the 4-2-1 but the other question is, which sensor goes in to the 4-2-1 manifold? The sensor before the cat in my manifold or the sensor after the cat in my manifold?

Cheers.

[kris]

one sensor is a before and the other is an after. Yours is just the same as mine mate and they are Lambda Planar Sensors. the top one goes into the sleeve and the bottom one goes into the manifold

[MoonstoneGTi]

Both are lambda sensors:) One pre-CAT & one post-CAT. I think they started having the 2 instead of one around 2001.

[Dave-R]

Cheers guys. I knew they were both lambda sensors but I was wondering if they measured different things and if they did, that would probably have a bearing on which one went in to the 4-2-1.

But if they're both exactly the same, it's all good.

Yes, Pug decided to change quite a few things around 2001, such as two lambda sensors, the cat in the manifold, different oil filter etc. I think on Peugeot's Service Box, 2001+ models are known as "technical depolution".

[samco77on]

the one before the cat goes in the manifold as this is for fueling so the ecu knows if the car is running rich, the one after is the one that goes in the sleeve as this just lets the car know if the air is cleaner (which in the sleeve it is) so it thinks its fine.

if u put the first one in the sleeve ur car will go mental mental chicken oriental.

[Dave-R]

Thanks Sam. Much love.

Hopefully the 4-2-1 will arrive before the weekend so I can whack the heat wrap on and then fit it at the weekend. Not loving the 106 tractor sound with the blowing fanimold at the moment.

[samco77on]

cool man, im back from uni for good this weekend, so we will have to meet up or sumthin.

just remember to put the right one in, lol. literally the second one is just to put the light on, so that you know the cat is fucked.

[Dave-R]

If I get them wrong, the car probably won't idle, hesitate, seem like its got a misfire? Should be pretty easy to spot. At the moment, the post-cat sensor is cable tied around my induction kit, with part of the OE manifold still attached to it. Fecking French crap!

We'll have to organise another meet. Want to arrange a rolling road day within the next few months too.

Thanks for your help bud.

[samco77on]

yeh u said that b4, i wud b up for that 4 sure. spk soon.

and if you put the wrong one in, it can **** ur engine. lambda sensors work by watching the stochiometric mix and when it goes lean, it corrects it, and when it goes rich it corrects it. so it sort of wanders. so if the lambda isnt working properly the ecu will wander the mix (say lean for example) and when the lambda doesnt feedback, it will go more lean, and more. etc. or it could go richer and richer. so could bugger u bigtime.

[MoonstoneGTi]

Useful diagram here:)

http://lambdapower.co.uk/TechNotes/Tech-1.asp

[D4LLV]

hey guys, i currently have this problem too. my sensor snaped out and i draged it around on teh floor for about 5 miles b4 i could stop an inspect what all the noise ywas about. i spoke to pug and they gonna charge me something stupid like £145 for a sensor and £210 for a new pipe. does any one know if there is anything i can do to avoid this??? i dont mind paying out for a better manifold etc aslong as its gonna be worth it?

[samco77on]

i wouldnt get a sensor from pug if its that expensive, try bosch ones, maybe from euro car parts?? or gsf (german swedish and french)??

as for the mani, u may aswell buy a raceland mate, if its 210 for a new 1, raceland is only 128 with club discount. hope this helps you.