Emission MOT fail 1997 1600

[hanlomike]

garage having problems with getting emission through MOT any thoughts

[martin1810]

You need to post the actual emission figures.

[hanlomike]

Exhast Emissions carbon monoxide content after 2nd fast idle 7.3.2
Exhast Emissions carbon monoxide content at idle 7.3.2c

[kenney]

Hi If your vehicle is a diesel,in many cases,it is could help,with the engine warm,give the vehicle a good hard run,before measurements are taken.

[hanlomike]

The car is a 1997 Passatt 1600 petrol . It has been losing power almost completly then picking up again the lamba sensor and another which regulates the cars themosstic contols have also beem replaced. Could it be the MAF sensor

[kenney]

What is the engine code

[hanlomike]

It looks like 068223

[kenney]

That is the number the code is something like AFT or AEK in front of the number

[kenney]

A faulty air mass meter will affect the emissions,as will a faulty temp sensor.Has the air filter been checked?

[martin1810]

The symptoms look more like a faulty lambda sensor (I see you've changed this) or faulty cat. You really need the car on the mot gas tester while you disconnect the air mass meter.

[hanlomike]

A new Maf sensor did not solve the problem still reading .5 carbon momoxide emmission

[martin1810]

Might be worth swapping the lambda sensor again just incase. You could be needing a new cat.

[hanlomike]

The lambda is new so to the MAF and thermostatic sensors the cat has bee dropped and checked and seems OK
Having now read up it would all point to the lambda as the car was losing power completely before kicking back in and using a lot of fuel. The garage is now scratching their heads and now looking at the engine management system. Any other thoughts on how to reduce the emissions level to pass the MOT

[martin1810]

Hi Hanlomike. Do the cheap things first. New plugs, new air filter, fresh oil change. Stick some fuel system cleaner in the tank. If timing is adjustable make sure it's spot on and idle speed as low as possible. Is the cars thermostat missing or stuck open. Change temperature sensor in case ecu thinks engine is cold. Your garage can test the lambda sensor output voltage to see what it's dong. All the best

[hanlomike]

Thanks Martin will do - will keep you informed