Clio 172 lamda sensor

[driversdomainuk]

Hi

Trying to sort poor fuel economy from my clio sport 172. I have been told to replace my lambda sensor - but which one....I have two. One mid section and the other near the back box...

Cheers

PS - I have a crap alarm on the car which keeps going off - were alarms standard on this model..?

 

[Russ_16v]

You wont have one near the rear box mate, you will have a lambda before the cat and one just after

 

[driversdomainuk]

ok, so I have two. Should I replace both....only ask as people on here sounded like they were refering to "replacing the lamda" - i.e. just one...??

 

[Mark One]

Never bother replacing the one further downstream. It's just diagnostic as far as I can work out. All it does it turn on a light to say that your cat is f*cked.

I would definitely recommend replacing the upstream one. Just replaced mine literally an hour ago and it's already running much much better from cold. The one i took out had only been in there 5k miles ish!
I've found that my economy improved a lot from changing one in the past see here