lambda , post or after

[marmitethecat2009]

I know this kind of topic has been discussed before but just want to ask
check engine light comes on usualy lambda sensor , but which one is it more likely to be the one in
front of the cat or the one behind ? any ideas
G.

 

[MarcB]

I might be wrong but I'm going to say the one after the cat as I'm sure thats the one checking for clean air.

I might be wrong tho.

 

[Amos91]

I thought both would bring up the engine light if there is a fault? Would need to be plugged into diagnostics to easily confirm.

 

[da rok]

both can bring up the light, however the pre lambda sensor (before the cat) is used for the fuel mix, the post lambda dosnt influence the mix and is just there to make sure that the cat is working...

 

[Carlv8415]

If the light is on but the car seems to be running fine then I would say it's the one after the Cat

 

[marmitethecat2009]

thanks ,runs fine but gona have to get it plugged in anyhow to find out exactly what's going on, anyhow least of my worries now think my defaser is on its way out as its started doing a bit of wining
and when I accelerate it wines so got to investigate this as well , don't you just love French cars!!
there nearly as bad as Italian cars! G

 

[Carlv8415]

Dephasers done wine, they rattle at idle. Whine could possibly be PAS pump (cheaper fix than dephaser)

 

[marmitethecat2009]

well sumuts wining! i'll sort it thanks for the help .
G.