Nct Fail On Emissions?

emjv1

Well lads thought i'd update on the whole sorry mess.Sorry i bought the poxy car now.:mad: New cat went in last Friday and also he welded few small holes in exhaust tract and he put it through his own analyzer and it passed. Drove it for the last week with Dipetane and FAILED Nct AGAIN yesterday!! Which means it has to go through whole test again and god knows what else they will find then. Results as follows:

1st Test: temp105c 2nd Test: temp 81c
High Idle 2820rpm 2680rpm
Lambda 1.07 1.01 PASS
CO 0.83 0.36 FAIL above 30 fail
HC 479ppm 335ppm FAIL above 200 fail

So the lambda has passed prob due to welding holes, the cat did not fix original problems. Everything better but not enough. Ideas please??

kazul

Spurious or genuine CAT? Spurious ones are crap, you should feel the weight difference. I opted against a Bosal spurious one for my car and got a 2nd hand one from a scrappie instead, passed 2 NCTS since (just)

emjv1

kazul wrote: »

Spurious or genuine CAT? Spurious ones are crap, you should feel the weight difference. I opted against a Bosal spurious one for my car and got a 2nd hand one from a scrappie instead, passed 2 NCTS since (just)

He said it was Bosal, said it would last better than 1 i wanted 2 buy from internet.

itarumaa

emjv1 wrote: »

Well lads thought i'd update on the whole sorry mess.Sorry i bought the poxy car now.:mad: New cat went in last Friday and also he welded few small holes in exhaust tract and he put it through his own analyzer and it passed. Drove it for the last week with Dipetane and FAILED Nct AGAIN yesterday!! Which means it has to go through whole test again and god knows what else they will find then. Results as follows:

1st Test: temp105c 2nd Test: temp 81c
High Idle 2820rpm 2680rpm
Lambda 1.07 1.01 PASS
CO 0.83 0.36 FAIL above 30 fail
HC 479ppm 335ppm FAIL above 200 fail

So the lambda has passed prob due to welding holes, the cat did not fix original problems. Everything better but not enough. Ideas please??

You have been informed that car is running rich, you have informed that you should not change the cat because that is not the problem and still you go ahead and change the cat and use Dipetane even many people said that it might not work.

Also from your post:
"The Nct man said it's running rich and misfiring but that means nothing to me "

That is the problem with your car and that is the problem have been there from the start.

What color were the sparkplugs when they were changed, black?
Do you get spark in every spark plug? Is the car running at all cylinders, have you checked ignition coil and leads?

You need to find out why the car is running rich or find a good person to find it out, not just change part after part and hope for the best and it would not hurt to actually read and follow the advice you get. I informed you at the first page that the car is running rich and it still does. That is the reason your HC value is high, because High HC means that you car is not burning all the petrol it gets.

kazul

emjv1 wrote: »

He said it was Bosal, said it would last better than 1 i wanted 2 buy from internet.

He also wasn't going to make money on the sale if you bought one off the net. Bosal CATs are an inferior product IMO

biko

Well what you've done so far has lowered the emissions significantly.
There's a good read here

If the HC is very high and the CO is close, you probably have an ignition/ compression related problem. Check the ignition system first. This usually caused by an ignition miss. Then check the engine. Poorly seated valves, leaking head gaskets, or other compression problems will put the HC readings through the roof. Also check for vacuum leaks and the injector spray patterns. Remember, HC failures are usually caused by compression or ignition problems. Improper fuel distribution/vacuum leaks will cause misfires that will cause excessive HC.

emjv1

itarumaa wrote: »

You have been informed that car is running rich, you have informed that you should not change the cat because that is not the problem and still you go ahead and change the cat and use Dipetane even many people said that it might not work.

Also from your post:
"The Nct man said it's running rich and misfiring but that means nothing to me "

That is the problem with your car and that is the problem have been there from the start.

What color were the sparkplugs when they were changed, black?
Do you get spark in every spark plug? Is the car running at all cylinders, have you checked ignition coil and leads?

You need to find out why the car is running rich or find a good person to find it out, not just change part after part and hope for the best and it would not hurt to actually read and follow the advice you get. I informed you at the first page that the car is running rich and it still does. That is the reason your HC value is high, because High HC means that you car is not burning all the petrol it gets.

Really dont appreciate the tone of this reply. You seem to think i have a clue as to what i'm doing which i can happily tell you that i do not! An actual qualified mechanic is telling me what should and should not be done and i am following his advice but would like to supplement that with some helpful feedback from this forum, also i was told the cat wouldn't fix the lambda value not the HC or CO and something definitely helped as emissions are down. Also i have followed advice from people on here who told me to use dipetane and i have listened to you about the whole running rich issue but does that cause the high CO's also? HELPFUL, non insulting advice would be the way forward as i'm not a bloody mechanic

emjv1

Magnus wrote: »

Well what you've done so far has lowered the emissions significantly.
There's a good read here

If the HC is very high and the CO is close, you probably have an ignition/ compression related problem. Check the ignition system first. This usually caused by an ignition miss. Then check the engine. Poorly seated valves, leaking head gaskets, or other compression problems will put the HC readings through the roof. Also check for vacuum leaks and the injector spray patterns. Remember, HC failures are usually caused by compression or ignition problems. Improper fuel distribution/vacuum leaks will cause misfires that will cause excessive HC.

Thanks for your reply Magnus, have read the link and am better informed from it . It's great to find out what might be causing it instead of someone just telling you ur an idiot

samih

As the lambda is close to 1.00 now it basically means your oxygen and other sensors are most likely ok.

The high HC can definitely be caused by ignition problems. HC is unburned hyrdocarbons = fuel. No "modern" engine without really angry cam profile, for example, would produce so high HC even without cat. My last non-cat car had HC of approx 100 at idle. If your car misfires it will eventually lead to a cat failure so don't drive the until the fault is found.

I would tackle the ignition system next, i.e. new sparks, ignition leads, ditributor cap and rotor (if fitted).

Was the timing belt changed recently. Maybe the engine timing is off? That normally results in high HC too.

emjv1

samih wrote: »

As the lambda is close to 1.00 now it basically means your oxygen and other sensors are most likely ok.

The high HC can definitely be caused by ignition problems. HC is unburned hyrdocarbons = fuel. No "modern" engine without really angry cam profile, for example, would produce so high HC even without cat. My last non-cat car had HC of approx 100 at idle. If your car misfires it will eventually lead to a cat failure so don't drive the until the fault is found.

I would tackle the ignition system next, i.e. new sparks, ignition leads, ditributor cap and rotor (if fitted).

Was the timing belt changed recently. Maybe the engine timing is off? That normally results in high HC too.

So the timing belt could also be the problem? Car is at 66800 mileage now and as far as i know has not been changed so it needs to be looked at then? Not my car (bought it for other half) so i only drive it to nct, mechanics etc when it has to go and if the new cat goes aswell i'm settin it alight . Ill make sure ignition sources are looked at on Monday, thanks.

biko

From http://www.smogsearch.com/faq US site, hence "smog"

Carbon Monoxide (CO)*
CO is created when gasoline is not completely burned. High CO ( running rich ).

A list of common causes of CO related smog check failure:

1. Timing is not a big factor in CO production but check it anyway. Everything helps.
2. On older Carbureted vehicles you can have problems like a partially stuck choke plate.This is the moving steel plate on the top of your carburetor.
3. A leaking power valve on your carburetor can cause high CO and Smog Check failure.
4. A faulty carburetor can cause high CO and Smog Check failure.
5. A dirty air filter can cause high CO.
6. A common cause for high CO is a faulty Oxygen Sensor. This sensor tells the computer how to fine tune the air fuel ratio.
7. Other sensors like the M.A.P.sensor , C.T.S. sensor or the Air flow meter can also effect the CO level.
8. A faulty air injection system can cause high CO. This is the Smog pump and related components.
9. A faulty Catalytic Converter can cause high CO and Smog Check failure.
10. If your car has been running rich ( high CO ) you should change your oil after you get it repaired. When you have rich condition all the fuel cannot be burned, you start to saturate the motor oil with CO and HC. This in itself can also cause a rich condition.

Bawnmore

Ok, so I have the retest tomorrow and would love to not have to go through everything again! When the car went through first, it failed on a few small things (indicator broken etc) which are all fixed, and emissions.

Car was in bad need of a service and when I did service, by the look of the plugs, car was only firing on 2/3 and were very "caked" over. I've been told that this would ruin the cat pretty fast. So after a service, CO level was down to .5 (must be under .3). Got the cat done today and thought it would be the end of it, but no luck.

Before the new cat, results were as follows:

High Idle
CO 1.2%
HC 359 ppm
Lambda 1.002
Oil Temp 85C
RPM 2660 min

Low Idle
CO 0.66%
HC 336ppm
Oil Temp 85C
RPM 760 min

So a fail on High Idle C0 and HC, and low idle Co.

After cat, results are now:

High Idle
CO .4%
HC 77 ppm
Lambda 0.985
Oil Temp 88C
RPM 3050 min

Low Idle
CO 0.39%
HC 85ppm
Oil Temp 88C
RPM 830 min

So just .11 over the C0 limit on high idle.

Garage said I needed to get a lambda sensor and that a universal (only one available to me on short notice) would be no good to me. Final peice of advise was to make sure the engine was as warm as possible going in.

So I suppose the question is - is there any way, if using the advise above in this thread, I'll be able to give that final push to pass??

Any advise at all would be HUGELY appreciated!!

Bawnmore

anybody at all??? Hitting the road now so won't have a chance to check again until later! Sorry for the bump, desperate

jonage

I fail nct for emissions; low idle CO .55 (above .5 fail) , high idle; CO .8 (above .3 fail), lambda 1.02 (pass), HC 103 ppm (above 200 - pass), so its only CO not much, I guess.. Have retest wendesday, filters and all checked before first one. I wonder- will botle of Wynnes pass me through this time? Any passed users with similar? Should I put whole bottle for half or full tank? Thanks for any advises.

Merch

I'm listening wrote: »

Yeah Zilog is right, very broad area.
I'm just going on my experience and that of a relative who also failed NCT due to emissions.
Yours might not necessarily be the same.

Hopefully doesn't cost ya that much.

your relative failed an NCT for emissions! ok sorry thats childish

emjv1 wrote: »

Been to 4 different garages and they all contradict each other as to the cause of emissions. One said dipetane wouldnt help, emissions too high. other said a change of filters,oil etc would not make any difference at all. One tried to change the converter without even looking at car and all this has left me more confused than before, god i hate mechanics!

the what? a converter? huh?

emjv1 wrote: »

The car just had its re-test this morning and everything is worse!!

BEFORE: High Idle(2830rpm) AFTER: High Idle(2820rpm)
Lambda: 1.05 Lambda: 1.07
CO: 0.77% CO: 0.83%
HC: 403ppm HC: 479ppm

Cannot understand how it's so bad. Car has been serviced last week and a broken centre box repaired. Also ran Dipetane through it for the last few days and gave it a really good run to the centre. Has anyone any more ideas of what could cause this in the space of a week? The Nct man said it's running rich and misfiring but that means nothing to me

What? a centre box, can you be more specific? a service may help, but if there is another problem
the timing is off/can check if your ignition coil/s are functional (and spark plugs plus leads)

Bring it to a mechanic that can tell you if

emjv1 wrote: »

Well lads thought i'd update on the whole sorry mess.Sorry i bought the poxy car now.:mad: New cat went in last Friday and also he welded few small holes in exhaust tract and he put it through his own analyzer and it passed. Drove it for the last week with Dipetane and FAILED Nct AGAIN yesterday!! Which means it has to go through whole test again and god knows what else they will find then. Results as follows:

1st Test: temp105c 2nd Test: temp 81c
High Idle 2820rpm 2680rpm
Lambda 1.07 1.01 PASS
CO 0.83 0.36 FAIL above 30 fail
HC 479ppm 335ppm FAIL above 200 fail

So the lambda has passed prob due to welding holes, the cat did not fix original problems. Everything better but not enough. Ideas please??

I'm kinda surprised you opted to change the CAT without getting the timing checked, ie the ignition items Coil/plugs/leads

itarumaa wrote: »

You have been informed that car is running rich, you have informed that you should not change the cat because that is not the problem and still you go ahead and change the cat and use Dipetane even many people said that it might not work.

Also from your post:
"The Nct man said it's running rich and misfiring but that means nothing to me "

That is the problem with your car and that is the problem have been there from the start.

What color were the sparkplugs when they were changed, black?
Do you get spark in every spark plug? Is the car running at all cylinders, have you checked ignition coil and leads?

You need to find out why the car is running rich or find a good person to find it out, not just change part after part and hope for the best and it would not hurt to actually read and follow the advice you get. I informed you at the first page that the car is running rich and it still does. That is the reason your HC value is high, because High HC means that you car is not burning all the petrol it gets.

I agree with this guy

-Chris-

You're replying to posts from Feb of last year. I'm sure it's sorted by now.

Thread closed.