MOT Fail on High CO2 and High lambda

[Sebastian1_1]

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.

[davey_83]

Recently similar happen to @Phil T with his HR, ended up taking it elsewhere nothing done to the car and it passed - put it down to calibration of the first places testing equipment perhaps.

 

Your test results show as the engine/exhaust we're getting hotter the figures were getting better/cleaner. You'd benefit from a 15mins Italian tune up and test it as soon as you got back to the test station.

Edited April 5, 2023 by davey_83

[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. 

[Laurence C]

Stick a bottle of injector cleaner in her. Not saying it will fix it but would do no hurt. I used that when I fitted the EFI to my Triumph Gt6 20 years ago because injectors were old and been kicking about a long time dry. That sorted them.

 

Edited April 5, 2023 by Laurence C