Clio - NCT Failure

veron01

My Clio failed the NCT due to very high emissions. A mechanic was saying that I should have driven it very hard before I went in and it would have passed. But isn't that only masking a problem?

Has anyone else had this problem before.

BrianD3

Is it diesel or petrol? What year is the car?

If it's a 93 or later petrol car it will need a functioining catalytic converter to pass the emissions test. Your cat could well be ****ed. A new one will cost around 300-400 euros. However it's not necesarily the cat - could be something like a dodgy ECU temperature sender.

If it's a diesel, the injectors might need cleaning (I believe these can be cleaned by putting them in a sonic bath)

If the emissions are very high and way over the limit, I doubt that just giving the car a good thrashing directly before the test will do the job.

BrianD3

veron01

It is a 2000 petrol.

Hope its not the catalytic converter or I am f****d never mind the CAT.

mike65

I'd head to a garage with an exhaust gas anyliser (sp)
that checks CO, NOX, particulates etc and get them to
check over the fuel/air mixture.

Newer catalytic converters have a two part design. The front half is a "three-way" catalyst, which burns various pollutants, and reduces hydrocarbons, carbon monoxide, and oxides of nitrogen into water, carbon dioxide and nitrogen. These converters require exact fuel air mixtures in order to maintain efficient exhaust reduction. The rear section of these converters is the normal oxidation catalyst that further reduces hydrocarbons and carbon monoxide. Air from the air pump is injected into the center of these converters. Here the air is allowed to mix with the exhaust before it passes into the oxidation catalyst, where it burns off its toxic chemicals and reduces emissions.

Mike.

dogz

failed me on someting similar 3 times. It was tehir F**K up though their machine was set to 6 cylinders and not 4 get them to make sure of thak If your idle revs are very very low according to the printout theres your problem

DukeDredd

Most of the time it turns out to be a tiny problem. I had the same and took it to the main dealer who sorted it out for 30 squid.