failed mot on emissions

hi, all. my mk1 golf gti 1.8 injection failed its mot. The co2 is at about 6.5% and the o2 s high at around 8-9%. took it to powerzone tuning and he thought it could be because of the fuel pressure which meens the metering head is playing up. Could it also be the warm up regulator? what do you guys suggest?

cheers, adam

i usually adjust mine before taking it in.


Use the CO2 adjustment in the top of the air box.

Then when it passes, turn it back up.

Al

alplatt said

i usually adjust mine before taking it in.


Use the CO2 adjustment in the top of the air box.

Then when it passes, turn it back up.

Al

ye he adjusted that, the co2 does drop but the o2 stays high and it shouldn't be doing that…

Firstly - get the terms right - you don't really check CO2, you check CO. High O2? So you're using a wideband? If its that high and the engine is running, I'd suggest its not firing on all cylinders - what's the HC figure? And….if its doing this, it should be plainly obvious there's a misfire.