lambda sensor

[scottthurlow]

i had my cat back system fitted the other day and was going to have a decat but the vts has it in the centre pipe, there is a lambda sensor just after the cat which i assume would need to be re fitted to giv the reading. how do i go about doing this, the bloke who fitted it said that removing the cat wouldnt make much diff to perfomance!

who have other done it???

[Slugshead]

I decatted my westcoast and it was fab

Only had the one lamba there mind, lot more free revving and the noise was fantastic

Hoping to decat my S but, im still unsure if there's 2 lambdas or just the one... if theres just 1 before the cat then go ahead and do it, will be awesome...

If not im guessing a simulator will need to be fitted to ensure that the engine management light wont come on..

If theres two the first one will say "ok about to go in the cat theres X oxygen in the mix"
Second one (after cat) "ok and now im reading this much"
ecu compares and adjusts mixture

if they read the same the management light will come on...

[MJ05LLY]

Dont you have to use a blanking sleeve if using a decat pipe for the sensor? This is what am led to believe.

[saxova]

Your meant to so it still reads fresh air.

But that way all your doing is tricking the management light to stay off. If the mixture is wrong, it won't pick it up, as the 2nd lambda isn't in the exhaust system.

Personally i haven't had either lamba sensor connected since de-catting. And it's been fine, no over fueling or anything.

[LeeM]

second lambda needs sleeving. if you dont the eml light will come on but it wont affect the running of the engine

[saxova]

^^^^^ or the dashboard taping lol.

[LeeM]

its easier to just sleeve it

[scottthurlow]

i dont get what u mean by sleeving it, it screwed into the cat pipe at them moment!

[LeeM]

you unscrew it and screw it into a piece of metal tube which is solid at one end

[johnnyg_vts]

hey presto.
http://www.gmcmotorsport.co.uk/index.php?main_page=product_info&cPath=62&products_id=186

[Slugshead]

is it really that easy to foool the sensor? will this damage it in any way?

[LeeM]

its that easy. it wont cause any damage