Corolla failed NCT on emissions

zetecescort · 01-07-2015 8:47pm #1

2000 vvti corolla failed emissions as shown in pic. burns a bit of oil as these usually do, not sure how much as its not my car. any tips for reducing the CO readings at high idle?

thanks

George Dalton · 01-07-2015 9:16pm

Looks like it needs a catalytic converter.

zetecescort · 02-07-2015 11:22am

does a high CO reading mean unburnt fuel? this is what the plugs look like. going to change them anyway but could they be the problem?

will try dipetane before retest and drive it on a bit and see what happens

joujoujou · 02-07-2015 12:27pm

Add a dipetane and drive it like you stole it - for at least a week.

And make sure engine is well heated up prior to a test.

Atlantic Dawn · 02-07-2015 12:35pm

Would sitting in the car parked up with the engine running before the engine impact on this or are they well beyond the figures that would give?

joujoujou · 02-07-2015 12:38pm

Atlantic Dawn wrote: »

[...] sitting in the car parked up with the engine running [...]

Did that twice.

Passed.

zetecescort · 30-07-2015 6:59pm

sorry for not getting back sooner. passed the retest but just about, reading of 1.03 which is bang on the upper limit. added the dipetane but it was mostly town driving that week for work so may not have worked as good as it would with motorway driving?

thanks for the advice

Atlantic Dawn · 30-07-2015 7:13pm

Great so just adding the dipetane and a good drive sorted it?

zetecescort · 30-07-2015 8:26pm

yeah, changed the plugs too so I guess it all helps a little

up-&-at-dem · 30-07-2015 10:47pm

Hi zetecescort

I have the exact same issue as yourself:

I have a Peugoet 206 '03. Failed on high emissions CO 0.24% (above .20% is a fail)

I threw in 3/4 litre of dipetane and half tank of petrol but failed and failed again with CO 0.37% (actually increased the emissions!).

I didn't drive it enough before the test. I didn't change the plugs either.

How much dipetane and petrol did you use?

cletus · 31-07-2015 1:17am

up-&-at-dem wrote: »

Hi zetecescort

I have the exact same issue as yourself:

I have a Peugoet 206 '03. Failed on high emissions CO 0.24% (above .20% is a fail)

I threw in 3/4 litre of dipetane and half tank of petrol but failed and failed again with CO 0.37% (actually increased the emissions!).

I didn't drive it enough before the test. I didn't change the plugs either.

How much dipetane and petrol did you use?

It says on the side of the bottle how much to use. Dipetene only works if you drive the car, it had to be run through the engine. It won't do anything sitting in the tank

Chirps92 · 10-11-2015 10:12pm

I have a 98 Toyota Corolla. It's a 1.3 vvti with just over 120,000 miles. It failed the nct on emissions (by .2) which is nothing. The guy on the nct suggested a new standard exhaust (I had a jap style one on) and a new cat converter. I had a new standard exhaust box and cat converter fitted and it still failed the nct again (worse this time). I then had a new lamda fitted and I also used dipetane a week before another nct and drive the hell out of it but it still failed again. The latest readings seem worse than the initial fail and they suggest the cat converter is too high and the lamda is too low...any ideas what's my next step?

mullingar · 10-11-2015 11:06pm

A high CO is usually caused by the engine running rich or a leaky exhaust.

An engine runs rich during warm up, but a faulty lambda (oxygen) sensor or as simple as a blocked air filter can also cause it.

Always try the simple things first, make sure it's toasty with a clean air filter with no exhaust leak

Corolla failed NCT on emissions

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