MOT CO2

[Baker]

car failed MOT on emissions today, but passed after we both fiddled with a few things, and also after i pulled the below vacuum hose.

for reference, with it on it was 6%, with off 0.18%!!



might be worth knowing if ur struggling with your emissions, even if cheating.

[Sidewinder]

The blue-ish looking hose in the middle of your picture?

Hmm...

[Mark Edwards]

Rather than cheating, wouldn't it be a good idea to solve the problem of it being that high in the first place.

[Baker]

Rather than cheating, wouldn't it be a good idea to solve the problem of it being that high in the first place.

thought someone might say that.

ordering an o2 sensor which seems the likely problem.

and yes, the blue hose in the middle is the one. maybe this should be partly blocked internally as that had the same effect when squeezed.

[BenF]

That'll let unmetered air into the intake, causing the engine to run really lean.

The 'better' solution is to use the idle speed adjustment screw on the AFM if you have a Rev1 or 2 Turbo - set it to let more air in.

If you can, also check the output from the O2 sensor - make sure at a 2,500 rpms speed you're seeing it pulse 4-6 times a second.

[Baker]

thats the first thing i tried, but it made little difference.
thought i'd bring this post up again after a year incase it helps anyone with their emissions.