Emissions Query?

[billy_s]

Bought a 2000 GS for my daughter as a first car. It came with a full MOT and had only 48K on the clock from new.

I checked the paperwork given to me by the seller and noticed that despite having been fitted with a new cat and exhaust parts less than a year ago (October 2011) the recorded emissions were very close to the permissable limits:- CO = 0.20% (right on the limit), HC = 198ppm (limit is 200ppm) and the sensor reading 1.011 (limit = 0.97 - 1.03). The test had run for 8 minutes.

The previous (September 2011) MOT emission test with the old cat when the car had done 43K recorded CO = 0.00%, HC 13 ppm and th sensor reading as 0.999 (test run for 5 minutes).

The car has not had a service since September 2010 when it had a recorded mileage of 41K. I am assuming it still has the original plugs and am planning to get it serviced at a local independent this week.

I was wondering if people thought the recorded readings for 2012 are indicating a problem with the recently fitted cat or is it more likely that the car is in need of a full service including plugs and filters? Do you think it would be worth asking the garage to run an emissions test again after they have completed the service?

The car seems to be running ok and there is no sign of oil leaks etc.

Any thoughts and advice welcomed.

Cheers

Billy

[Madasafish]

Check the make of catalyst supplied. Some aftermarket ones are rubbish. Probably needs a burst of hard driving to clear the engine of accumulated carbon from short trips. And new plugs and filters.

If it's still poor, the lambda sensors may be faulty - but you should see warning lights if they are.

[billy_s]

Check the make of catalyst supplied. Some aftermarket ones are rubbish. Probably needs a burst of hard driving to clear the engine of accumulated carbon from short trips. And new plugs and filters.

If it's still poor, the lambda sensors may be faulty - but you should see warning lights if they are.

Many thanks for the advice. No sign of a warning light so the sensor looks good.

It would appear that car has mainly been used for town driving. I will give it a good run with plenty of revs. Getting a full service on Thursday. I wouldn't be surprised if it is still running on the original plugs.

Cheers

Billy

[MikeSh]

You need sustained power rather than revs - you need to get the exhaust system HOT.

eg. after its warmed up fully do 15-20 mins at 70 mph or maybe up a long steep hill a few times.

[billy_s]

You need sustained power rather than revs - you need to get the exhaust system HOT.

eg. after its warmed up fully do 15-20 mins at 70 mph or maybe up a long steep hill a few times.

Thanks Mike. Will give it a good run as you suggest.

[mark999]

Lambda sensor problems dont always giva a light on the dash. Do a scan for fault codes. Some engines do not like generic aftermarket lambda sensors, may be worth checking if it has been replaced with one (wires taped together is a good sign its not a direct fit replacement)

Mark