NCT failed on emissions

kieran--f

Hi, has anyone any tips on getting through the NCT emissions test after the following fail. My car is a 03 Golf mk4 1.4. The car had been sitting for three weeks before the test with the exhaust off. I drive a work van everyday and had left the exhaust with a friend for welding. I stuck it back on the morning of the test and drove in. I'm thinking maybe with a hard drive, some of that redex stuff and a service I might just scrape it. Thoughts?

Engine oil temp : 110
Low Idle CO 1.06% (above 0.3 = fail)
Lambda 1.01 (Pass)
High Idle CO 0.03% (above 0.2 = fail)

To me it would seem like the engine was maybe still cold at the low idle?

biko

Engine oil temp is 110, that is not cold by any means.
Many sheets I see are 80/90 but some are over 100 like yours.

You could try system fuels cleaners/dipetane and drive it hard a few days to clear out the system but it could actually be an issue somewhere.
Is car smoky? If so colour?
Any engine work lately except welding on the exhaust?
Why was that needed?
Are you sure sensors are ok?

firstlight

kieran--f wrote: »

Hi, has anyone any tips on getting through the NCT emissions test after the following fail. My car is a 03 Golf mk4 1.4. The car had been sitting for three weeks before the test with the exhaust off. I drive a work van everyday and had left the exhaust with a friend for welding. I stuck it back on the morning of the test and drove in. I'm thinking maybe with a hard drive, some of that redex stuff and a service I might just scrape it. Thoughts?

Engine oil temp : 110
Low Idle CO 1.06% (above 0.3 = fail)
Lambda 1.01 (Pass)
High Idle CO 0.03% (above 0.2 = fail)

To me it would seem like the engine was maybe still cold at the low idle?

Few bottles of dipetane and drive it hard in every gear for a few days
Always worked for me,send it in red hot
110 seems fairly hot anyway
Might just need a long drive to clean it out
Chance a oil change and air filter, lambda sensor could also be culprit

kieran--f

Thanks guys, im going to change the oil, oil filter, air filter, plugs and spray all the intake with carb cleaner. Run down a full tank with dipetane and maybe throw some more in again on the morning of the test. I dont really have a reason to think anything is electrically faulty. It drinks a small bit of oil but no more than is normal enough with these golfs.
I do know the cat is bet however, when I pulled off the exhaust for welding there was a bit of black comb rattling in it, it wouldnt be worth changing the cat though on this car

firstlight

Ye fire some more in on the morning of the test,i used to let the tank go down to a 1/4 and put in a high concentrate
Most from that age use oil,i know the brothers 1.4 golf 2002 did,was regularly topping up
I wouldnt be sure on the cat

Good luck with it anyway

kieran--f

firstlight wrote: »

Ye fire some more in on the morning of the test,i used to let the tank go down to a 1/4 and put in a high concentrate
Most from that age use oil,i know the brothers 1.4 golf 2002 did,was regularly topping up
I wouldnt be sure on the cat

Good luck with it anyway

Passed today had .27 CO and all I did was a service and cleaned the throttle body plus add dipetane to the tank and give her a hard drive. Thanks for the tips.