Modified S3 throwing up a niggling problem. Any ideas??

[LukeB90]

Hi guys, My mates s3 has been revving on idle and holding its revs when foot is off the gas. PCV has been changed, engine management light is on and the fault that's been thrown up is the Lambda sensor. Car has full milltek turbo back exhaust, a map, anti lag and a filter think that's about it. Could any of these be creating an issue?
As always any help would be much appreciated.
Cheers Guys

 

[HansfishS3]

Has he got a decat pipe? And has that been coded out in the map?

 

[LukeB90]

Just spoke to him, he said he had the exhaust done after the map but never got it mapped after. Do you think this could be the reason?

 

[HansfishS3]

If it's got a decat then the EML needs to be coded out, does it have a decat?

 

[LukeB90]

Yes it has a decat mate

 

[HansfishS3]

Needs coding out

 

[LukeB90]

Ok thanks I'll let him know

 

[paddy]

Does your mate not join forums ?

 

[leshkin]

Does your mate not join forums ?

Was going to say - would probably make things much simpler

 

[LukeB90]

Believe me I've tried haha. I don't get it either