Sebastian1_1

Thanks for your reply. Ill have a word with my mot centre or go to another one. 

Ill probably still get the mechanic to investigate the fueling issue still. 

Just had MOT done and it failed with high co2 readings and high lambda readings which confuses me as that contradicts each other?

Fast Idle Test:

CO2 - Max 0.20% - 0.63% Fail

HC - Max 200ppm - 60ppm Pass

Lambda - 0.97/1.03 - 1.06 Fail 

Second Fast Idle Test:

CO2 - Max 0.20% - 0.24% Fail

HC - Max 200ppm - 52ppm Pass

Lambda - 0.97/1.03 - 1.04 Fail 

Natural Idle Test:

CO2 - Max 0.20% - 0.16% Pass

Had a mechanic plug in a computer and he said one bank is under fueling and the other bank is over fueling.

If anyone has any ideas what it could be or could point me in the right directon of what could be the issue would help?

2007 350Z VQ35HR. Previous owner fitted Cobra Exhust and had an engine tune by 30hp.