slightly high lambda reading on idle whilst warm

[chrism]

Im off to mot the motor tomorrow so I gave the car a spin today. The lambda reading was perfect both on idle and cruising ie 1.00. I stopped to get some messages and when I came out my lambda on tickover was a bit higher:about 1.05 to 1.10, sometimes down towards 1.03. 1.03 is the limit for lambda readings here during mot. The lambda reading whilst crusing home was perfect though.

Anyone got any ideas why this happened?

Regards.

 

[chrism]

lambda 1 = afr 14.7
lambda 1.05=afr 15.44
lambda 1.10=afr 16.7

 

[PobodY]

How's the earth on your MAF? - I'm pretty sure that's where you adjust your idle mixture (there's a trim pot inside it, but I've never got the lid off mine).

 

[chrism]

Just fitted a new maf a q45/p60. I wont be taking the lid off this one though. When u take the lid off you break the soldered joint underneath

Im thinking an exhaust leak but Im not sure why Im getting the dodgy reading after its warm.

 

[danr]

titanium lambdas take a bit longer to heat up, but once hot stay hot ready for restarts. could just be its got up to optimum temp

 

[geoff pine]

lambda 1 = afr 14.7
lambda 1.05=afr 15.44
lambda 1.10=afr 16.7

Is it me or are these figures all a bit lean for a gtir im sure mine on idle is around 12.6 /13. once warmed up 14.7 is for a none turbo-ed car ????

 

[chrism]

It should still be 14.7 on a turbo on idle. ie a lambda reading of 1.00

 

[chrism]

It passed its mot yesterday without any problems at all. Chuffed.