Wideband Lamba sensor position

[adyw]

Can anyone help with a picture or two, I need to get the boss for my new wideband lamba sensor fitted to the car for new ECU fit, Now the manual says before the cat ( still have standard exhaust system) but at the point where all cylinders meet, this means there is not much room, is there a best position
Can anyone help?

[The AJP Griff]

I ran mine,very sucessfully,after the main cat but before the joint from downpipe to exhaust.It's a nice positon where the gasses are well blended

[CHGRIFF]

Manifolds should be de-catted as the cat influences the gas output. It will work but wont give correct readings. The manual is correct and giving good advice. Best to de-cat and fit wide band lamda where the cat sits.

[chrispitman]

I fitted mine in the side of the small pipe at base of the Y piece the sensor sits under the swirl pot as theres quite abit of room there. Mind you I have de catted manifolds and brought a secondhand Y piece with cat chopped out.

[lwt]

Mine is after the main cat and runs fine. Read up on how cats work and you will see that it is ok. It reads the oxygen left in the gas, and this is the same after the cat as before it. Ian.

[Uncle Fester]

While your doing the rest of the work, give your Griff a treat and get it a decat Y piece.

CliveF supplied one of his Y pieces with a wideband boss already fitted. Very nice job.

That way you still have the original cat Y piece if an MOT test ever gives problems.

[adyw]

Thanks gents, at the moment I don't think I have much choice other than install after the main cat

[Ballistic Banana]

I was told recently From a very reliable source if I was to install the Lambda in the y piece cat to put it before the cat rather than after..I didnt ask why though..

BB

[GreenV8S]

Mine is installed at the curved part of the manifold close to the original narrowband sensor, but lower down. I've got bosses on both sides but only one of them feeds the ECU. This means that it only reads one bank, but the way I see it there's no reason to expect the two banks to behave any differently.

[hiltonig]

I too have the same decision to make, its shame the Emerald only suports one lambda as the other makes support two for the V configuration

[trackcar]

Best ask emerald about the twin lambda thing, i felt sure Karl said it now supported twin lambdas or would be along very shortly. I've succesfully run lambdas after the main cat , there may be a couple of % mixture difference but I can't say i've ever noticed it. Many cars have a lambda before and after teh cat to measure the OSC (oxygen storage capacity I think) of the cat .. but I've run widebands after the cat and not hit any snags .. indeed generally mapping on the dyno we stick a probe up the exhaust tailpipe which is after any/all cats in the system and use that as a mixture reference so at the moment i'm strugling to see why it should matter a great deal.

Edited by trackcar on Thursday 24th April 08:12

[Pink_Floyd]

Is there any time lag problem with having the lambda sensor after the cat. I though that I read somewhere that you had to have the sensor before the cat, but on my sons Clio it is after the cat.
Just found this on the Ford site.
"There are also 2 associated Lambda (Heated Oxygen Sensors) mounted before and after each Cat. The first one measures the amount of Oxygen in the exhaust gas and is used by the EEC-V to adjust the mixture between rich and lean and the other monitors the efficiency of the Cat but is not used by the EEC-V."

Edited by Pink_Floyd on Friday 25th April 11:46