Lambda O2 sensor - Upper or lower?

Anything related to the 206CC
nzpug
Posts: 7
Joined: Mon Sep 24, 2018 10:46 am

Lambda O2 sensor - Upper or lower?

Post by nzpug »

ive been having lack of power issues with my 2005 pug 206cc 2.0 - it starts fine and idles ok but when you take off it can just lose all power and feel like its going to stall

initially i thought maybe it was the MAP sensor which i replaced but it hasnt made a lot of difference

now im thinking maybe its the o2 sensor - you can pick them up pretty cheap on aliexpress so i thought it was worth a shot.

just not sure of a couple of things

* are there 2 lambda sensors (one to monitor air/fuel - which i think is maybe the cause of the problem - and the other to monitor the cat)
* where are they located? (im guessing one is attached to the exhaust below the cat - see attached pic)
* are they interchangeable? or are they different part numbers (there seem to be some with a longer cable)
20180923_114157.jpg
20180923_111908.jpg
20180923_111953.jpg
thanks
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gazza82
Posts: 2126
Joined: Sat Apr 23, 2011 8:41 pm
Location: Buckinghamshire, UK

Re: Lambda O2 sensor - Upper or lower?

Post by gazza82 »

They are not interchangable as the cable length is also part of the circuit. Hence the pale blue and green connectors.

Get it on a diagnostic ... changing parts through guesswork is expensive ... and often unecessary.

Don't be fooled into buying cheap parts either. I swapped out a lambda on an Alfa at the suggestion of a specialist ... we fitted an NTK one as it was cheaper (and on his parts shelf). Turns out it was completely the wrong ohm rating and had to be replaced again with a Bosch one.
Last edited by gazza82 on Tue Sep 25, 2018 9:26 am, edited 1 time in total.
Family Fleet: ex-Cayman Green 206 CC 2.0 LE, Indigo Blue 206 1.4 HDi Hatchback, Subaru BRZ Auto, Alfa Romeo MiTo

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Capncol
Posts: 3761
Joined: Fri Nov 11, 2011 12:40 pm
Location: Reading & Southampton

Re: Lambda O2 sensor - Upper or lower?

Post by Capncol »

Get it on a diagnostic machine with someone that knows how to use it.
It will be a lot cheaper than parts scattergun approach in the long run.
Cheers Col.


206cc 1.6ltr (Wifes toy)
Mercedes ML (workhorse)
Corvette C3 (my toy)

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