2008 Opel Corsa 1.2 Petrol Emissions Fail NCT 16 TIMES OVER LIMIT!!!

jj880 · 10-11-2023 10:09am #1

NCT Tester said high idle fail could be small hole in the exhaust.

For the low idle fail he said "car running very rich. Something else besides the exhaust wrong for that".

Im not sure what the limit was last year but that seems like a mad CO amount. Over 16 times the limit allowed!!

Do the CO limits get tightened up when the car is over 15 years old? Car reg date is January 2008.

Anyway it's a shame because it didnt fail on anything else so brakes, steering, suspension etc all good.

Should I get the catalytic converter changed? New spark plugs?

Any ideas on how to get this CO reading down would be much appreciated.

Thanks.

Miscreant · 10-11-2023 12:19pm

The limits do not change over time for the car so you would have been tested at 0.30% last year as well. Newer cars are tested at 0.20% now AFAIK.

You need to get the car checked out by a decent garage but they should be able to read the stats easily enough. Your Lambda is well out so it could be as simple as a new sensor being needed to bring all the other results back into line and get you a pass.

jj880 · 10-11-2023 12:47pm

https://www.boards.ie/discussion/comment/121350612#Comment_121350612

A stats reading machine. I live in North Donegal. Just talked to my mechanic - he says that will be hard to find round here. Hopefully someone has such a machine in Letterkenny.

Re sensors. I did recently replace a MAP sensor that was giving a high voltage fault code P0108. Got a brand new Bosch MAP sensor and that cleared the fault code. Maybe thats unrelated.

Ok will ask around about the stats reader. Thanks.

jj880 · 11-11-2023 12:40pm

https://www.boards.ie/discussion/comment/121350612#Comment_121350612

I rang a garage near Letterkenny with an emissions stats tester. I gave them all my results and when I asked how much would it cost wouldn't give me a price. They told me the car would need to be left in for a day and you wouldnt get much done for a few 100 euro. Gangsters.

Im not up for that kind of nonsense to be honest. Id rather run the car into the ground. I found a guy with same CO results to me online and it turned out oil had been pushed from the pressure switch into the all the cable looms around the ECU causing the high CO readings. He cleaned the connections and throttle body and car passed the test. What you think?

Im willing to try something on this retest. I can have another test in January if I need to. Im 85 days away from my NCT date at the moment.

User1998 · 11-11-2023 12:54pm

https://www.boards.ie/discussion/comment/121354823#Comment_121354823

How are they gangsters? How are they supposed to diagnose it and price it over the phone all without even seeing the car?

jj880 · 11-11-2023 1:42pm

https://www.boards.ie/discussion/comment/121354864#Comment_121354864

They started talking about all the parts theyd have to order. I said Im just looking for a price to get the emission statistics read and we'd go from there depending on what the problem is. They refused to give me any kind of price even for that.

Ive never had to just hand over my car with absolutely no idea on cost for a service before. Am I being unreasonable? Genuine question.

User1998 · 11-11-2023 2:05pm

https://www.boards.ie/discussion/comment/121355020#Comment_121355020

Well it depends on the scenario, if you have a fault that could be multiple different things then it needs to be diagnosed first before a price can be given.

Obviously something basic like break pads or an oil change can be priced beforehand with no need to diagnose.

It seems like your fault falls in to the first category. Ideally they’d diagnose the car, let you know what it needs and how much it will cost, and if you don’t want to proceed then you just pay the diagnostic charge.

jj880 · 11-11-2023 2:15pm

https://www.boards.ie/discussion/comment/121355123#Comment_121355123

So I guess Im asking is it common practice to leave your car in for a diagnostic only with no idea on price beforehand?

If so fair enough but I wont be doing that.

User1998 · 11-11-2023 4:39pm

https://www.boards.ie/discussion/comment/121355166#Comment_121355166

Well a lot of people do and then get stung with a big surprise bill. So not the best idea.

jj880 · 11-11-2023 4:49pm

https://www.boards.ie/discussion/comment/121355717#Comment_121355717

It seems we're agreeing then. If a garage wont give a quote for diagnostic where does that leave me?

jj880 · 25-11-2023 8:17pm

Update. I went to a guy my mechanic recommended to help with emissions retest.

I left the car with him for 2 hours and he said car is ready for NCT emissions retest.

When I got home Ive noticed my OBD2 reader now doesn't connect up like it did before. When it tries to connect lots different lights go on and off on the dash as it goes through the different profiles. My retest is on Wednesday. So I have 2 questions:

1. Does the NCT emissions test use the OBD2 port or is car fine for the retest as is?

2. Is something wrong with my OBD2 port or is this normal after what the emissions mechanic did (remap?) and maybe it takes a while for the car to let me reconnect again?

User1998 · 25-11-2023 8:51pm

Its only a re test so they wont connect to it. Its only an advisory anyway not a fail. No idea whats wrong with it. It doesn’t need any time to let you connect again.

jj880 · 25-11-2023 8:56pm

https://www.boards.ie/discussion/comment/121418298#Comment_121418298

Ok thanks - I will put it through the restest then see how it is.

Considering the car was only with him for less than 2 hours Im guessing he did something through the OBD port and didnt take the ECU out to do something.

In the corsa d the OBD2 port is pretty awkward to get at. I hope they didnt feck it up trying to get at it somehow?

jj880 · 25-11-2023 9:05pm

1 more thing. A yellow engine warning light came on this morning. I obviously couldnt read the fault code as I cant connect to OBD now.

I drove car to petrol station. When I restarted car check engine light was gone. Car is running fine.

If per chance a yellow engine warning light comes on when they start the car in the NCT centre will they still do the emissions retest?

User1998 · 25-11-2023 9:48pm

They’ll still do the test but you should probably talk to your mechanic about the warning light and the OBD port

jj880 · 25-11-2023 10:06pm

https://www.boards.ie/discussion/comment/121418514#Comment_121418514

Ok will do. Im hoping the OBD pin connections need tightened up. That would be an easy enough fix.

jj880 · 26-11-2023 2:52pm

https://www.boards.ie/discussion/comment/121418514#Comment_121418514

Used compressed air on the obd port. Got it connected up. Fault is P1138. From the Corsa D UK forums:

Screenshot_2023-11-26-14-47-21-843_com.android.chrome-edit.jpg

So seems to be Lambda related. Thing is it goes away after a good hard run.

Typical. Only a few days before emissions retest.

I'll ring the emissions guy tomorrow to see what he says.

zg3409 · 26-11-2023 7:26pm

Do you have an idea what you "emissions guy" did? It sounds like whatever he did seemed to have made the car worse. High emissions can be many many things and it may take many hours and a good mechanic to be sure issue is resolved. Unless the person has an emissions tester they are only guessing if it's fixed.

Oops! · 26-11-2023 7:37pm

MOD Edit

jj880 · 26-11-2023 7:39pm

https://www.boards.ie/discussion/comment/121421689#Comment_121421689

I asked him was the car really bad. He said not that bad and its ready for the retest. As he was recommended by my mechanic who Ive been with for last 8 years I didnt want to grill him. He has an emissions tester I know that much. The car is driving fine no problems. It gave a warning light once and it hasnt came back since. Wouldnt the proof be in the emissions retest results?

jj880 · 26-11-2023 7:56pm

Just an fyi this is not my or my parents main car but we'd like to try keeping it on the road for my father to use for running dogs up in the hills near their house so my mother doesnt have to suffer dog smell in their everyday car. So car doesnt have to be in tip top shape but obviously we still need it through the NCT for another year if possible.

jj880 · 30-11-2023 9:20am

Retest from yesterday. That went well.

The NCT centre tester says the machine I got it tested on must have a faulty sensor as it was showing 0.01 CO on low idle 1 hour before the retest.

Car is running great even in cold snap here last few days.

Ive rung another garage. They think results like that means car needs a new airflow meter. Not sure what to do now to be honest. Got 10 days left if I want to retest again.

jj880 · 02-12-2023 6:32pm

Ok I've had the car read at another garage. Their machine is showing 0.00 and 00.01 CO so basically the same as the first garage. Both mechanics say theyve never seen anything like it. Both also say the car wouldnt be running or be running really badly at 8.84% CO but the car is running great. Now either they are both taking the p!ss or something really strange is happening. Ive 8 days left to retest. The 2nd mechanic has actually advised me to try a different NCT centre for a retest before the 8 days is up 😳. Here is the 2nd mechanics emissions tester readings (I took these) while 1 of his other mechanics was revving the car (they tested the car twice at low idle and twice at high idle):

low and high idle (cant remember which is which):

jj880 · 02-12-2023 6:36pm

https://www.boards.ie/discussion/comment/121421689#Comment_121421689

I since found out that the first mechanic didnt actually do anything apart from patch a small hole in the exhaust. Once he got the 0% CO reading after that he then told me car was ready for the retest. He charged me 40 euro so I suppose that makes sense for patch and emissions read.

User1998 · 03-12-2023 9:42pm

I’ve passed emissions tests in exhaust centres just like that and 10 minutes later in the NCT I fail miserably. Then go back to exhaust garage and pass their test. And if you complain to the NCT they just tell you to piss off.

jj880 · 03-12-2023 10:04pm

https://www.boards.ie/discussion/comment/121450715#Comment_121450715

NCT tester basically said that - told me whatever machine I was using has a faulty sensor. But now car is reading 0% CO on 2 machines outside of NCT centre. To quote 1 of the mechanics he said the car should be running like "a bag of shite" at 8% CO.

Is the machine in my photos the right kind or is there some other type of machine I should be looking for?

jj880 · 03-12-2023 10:59pm

https://www.boards.ie/discussion/comment/121450715#Comment_121450715

I really have no clue what to do. Car booked into different NCT centre an hour away on Thursday. 3 days after that back to square 1. The last mechanic made another comment. He says 8% CO sounds like unburned fuel. I'm thinking of changing the spark plugs before retest just to see if it make ANY difference at all.

Magown3 · 04-12-2023 7:11am

I was going to ask are you sure it's running on 4 cylinders as yes, unburnt fuel would have high results. Mechanic should have picked up on something like that.

Get 4 coils and 4 spark plugs.

Your hour journey to the nct centre, make it in 45 mins. Drive it like you stole it... Seriously

jj880 · 04-12-2023 8:10am

https://www.boards.ie/discussion/comment/121451393#Comment_121451393

Any time theres a cylinder misfire with this car I get a flashing engine warning light and code saying "misfire in cylinder X". Then car runs really rough until its sorted. Like you say usually new plugs and/or a pack. The coils are in 1 long block. I asked my main mechanic who services and he said plugs will make very little difference as car is running well. Which it is. Dont think I can go back to him now and demand a new set. Could always get another mechanic to do it.

Is car safe to drive like this? Does unburnt fuel go into the CAT?

EDIT: Im still in a spin over the 2 emissions machines showing 0.00 / 0.01% CO. With the mechanic advising a different NCT centre for retest he's not sure whats happening either. Its mad. If only I could get somewhere outside the NCT centre showing the same results. At least then could start from there to try and fix.

jj880 · 06-12-2023 6:45pm

Like Ive said car is running great but 1 thing I have definitely noticed is a strong smell of fuel sometimes right after ignition. It goes away after a minute or 2. What Im wondering is could the car be over fuelling at ignition causing these mad CO % readings when they do the emissions test as emissions is usually done straight away?

Is it allowed to arrive at the NCT centre and leave the car ticking over until they do the emissions retest?

jj880 · 07-12-2023 3:46pm

https://www.boards.ie/discussion/comment/121451393#Comment_121451393

In the end I didnt change anything on the car and Im glad I didnt. Car passed today at a different NCT centre.

FROM 4.99% CO AND 8.84% CO ON LOW IDLE DOWN TO 0.06. Ridiculous carry on.

I'm 56 euro down on retests + 50 euro for 2 emission readings. Both times mechanics were adamant the car was good and they were proven right.

As can be seen in the pics above in thread I have a photo of the clean reading from the mechanics emission reader.

Before anyone calls me a know all / f*ck all c*nt like in the posts that got removed from this thread by mods the following is a genuine question: Does anyone know if NCT centres entertain you if you look for money back?

@User1998

User1998 · 07-12-2023 3:53pm

No not a chance they’ll give you any money back. You won’t even get an apology. At least it passed in the end.

jj880 · 07-12-2023 4:05pm

https://www.boards.ie/discussion/comment/121467235#Comment_121467235

Thought as much.

Yeah I am glad it passed.

Tantalum73 · 08-12-2023 7:53pm

Your situation is exactly one of an intermittent fault , most probably your front o2 sensor starting to fail .

jj880 · 08-12-2023 8:31pm

https://www.boards.ie/discussion/comment/121472587#Comment_121472587

Would that not have some drain on performance? At 8.84% CO the emissions mechanic said the car should be running terrible. So even with an intermittent fault like you say surely I would have noticed something? Car been running great through all NCT tests / retests.

The only difference with the final retest was theres a dual carriageway for a few miles and at the end of it is the NCT centre. I drove like a bat out of hell the length of that dual carriageway and they tested as soon as I arrived. You can see 88c temperature on my pass sheet.

Tantalum73 · 08-12-2023 10:23pm

https://www.boards.ie/discussion/comment/121472705#Comment_121472705

No not necessarily as for the most part the o2 sensor could be working ok when the vehicle is being driven , when for example an o2 sensor is starting to fail, (slow switching or stick high/low) can be down to vibration , rpms and temperature . Again this is one probability amongst a whole host of others that could be the cause , but usually its the most common.

It is quite possible your drive to the test centre had an effect on the issue and went in your favour .

FWIW I am a master tech and qualified vehicle inspector.

jj880 · 08-12-2023 10:39pm

https://www.boards.ie/discussion/comment/121473187#Comment_121473187

Ok thanks. When you say O2 sensor is that the same as the airflow meter? As I did have 1 garage say the high CO % results suggest car needs a new airflow meter.

Tantalum73 · 08-12-2023 10:43pm

https://www.boards.ie/discussion/comment/121473251#Comment_121473251

Airflow meter is not an o2 sensor . The airflow meter will ''meter'' or "measure' the air volume entering the engine . The o2 sensor measures the air to fuel ratio in the exhaust . The garage could be right in that it has an issue but I would always ask why in their opinion it requires one and how much diagnostic work have they carried out to come to said conclusion .

jj880 · 08-12-2023 10:50pm

https://www.boards.ie/discussion/comment/121473269#Comment_121473269

Ok I did have a P1138 fault code a couple weeks ago. I just read car and its still there but no warning light anymore. Corsa UK forums say this is the lambda sensor that needs cleaning / replaced. Theres definitely something up. This car will only be driven locally as a run around but would still like to fix that code. Strange.

Tantalum73 · 08-12-2023 11:01pm

https://www.boards.ie/discussion/comment/121473296#Comment_121473296

If this car only sees short trips were the engine does not get up to temperature for a decent amount of time , the o2 sensor could get soot accumulation on it .