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Emissions mot issue

Posted: Tue Apr 25, 2023 10:40 am
by wurlycorner
Honestly the first thing to check for is vacuum leaks on all of the intake system and any leaks on the exhaust system between the manifold where it bolts to the head and the back of the cat.
If there are any faults there, (particularly if there are any minor leaks on the exhaust) the mixture will be out.
If you're running the standard manifold, that means unbolting the heatshield to check all of the manifold properly - the welds around the collector do crack and you're very unlikely to hear a leak there, just look for soot.

Emissions mot issue

Posted: Tue Apr 25, 2023 12:47 pm
by Wellhappy
vanzep wrote:
Mon Apr 24, 2023 5:30 pm
good plan - get it on the road as a rolling resto (just like the rest of us) :)
i normally put in some fuel line cleaner to help with emmisions - wurth petrol saver is a good one..but there are plenty out there to choose from. Old fuel could be an issue but its easy to drain it out - its just one 14mm bolt at the rear of the tank on the passenger side.
good luck with the re-mot ;)
Sorted a lot Today and sealed a hole in the exhaust at the back box, new sparks, Oil change, HT points sorted, filters done so trying the mot again tomorrow.. praying 🙏 lol everything else is ok no leaks from anywhere else… way less smoke now also out the back which of course is a positive sign :) plugged in and no codes at all so think the o2 sensors are all good :) I will update tomorrow:)

Emissions mot issue

Posted: Tue Apr 25, 2023 12:55 pm
by Wellhappy
Hmmm there was another reply here however it’s vanished lol how odd… maybe something I’ve done 🤔
My reply was we checked all the possible places for leaks land all seems perfect, tbh I think for what was paid it was an absolute steal, esp with all service stamps from Honda and the fact the water pump and cam belt was also done at 120k odd so that’s all good… if it fails tomorrow it’s the cat … so will just buy a new and better exhaust system :)

Emissions mot issue

Posted: Tue Apr 25, 2023 4:53 pm
by Wellhappy
Back to basics lol

Emissions mot issue

Posted: Tue Apr 25, 2023 9:25 pm
by JEBB4
Hello, emissions test failure on an old car like this could be many things.. if you say it’s a Lambda reading out of spec it could be as simple as a small vac/air leak on the intake or exhaust blowing. If there’s no engine light illuminating it’s probably not a complete failure of a sensor but more likely ageing of an o2 sensor, catalyst or contamination of a sensor..
if you have the readings from the test the tester should be able to determine what’s happening from the readings ie high o2, low o2, hydro carbons too high etc then give you an idea of what to look for.. good luck :thumbup:

Edit: I see you have checked many of the things I mentioned above

Emissions mot issue

Posted: Wed Apr 26, 2023 2:08 pm
by Wellhappy
JEBB4 wrote:
Tue Apr 25, 2023 9:25 pm
Hello, emissions test failure on an old car like this could be many things.. if you say it’s a Lambda reading out of spec it could be as simple as a small vac/air leak on the intake or exhaust blowing. If there’s no engine light illuminating it’s probably not a complete failure of a sensor but more likely ageing of an o2 sensor, catalyst or contamination of a sensor..
if you have the readings from the test the tester should be able to determine what’s happening from the readings ie high o2, low o2, hydro carbons too high etc then give you an idea of what to look for.. good luck :thumbup:

Edit: I see you have checked many of the things I mentioned above
well we got one level down to perfect but up shot the Co2 lol back the the drawing board lol maybe blast it through on the a1 for an hour at high revs …

Emissions mot issue

Posted: Wed Apr 26, 2023 2:15 pm
by Scott560
Once you have fixed any leak in the exhaust, it will take a while (and multiple restarts) for the engine fueling to be trimmed down. It's not always an instant thing, especially if the lambda sensor is tired or if the car hasn't driven much since the fix.

Not sure if the 2.0 has an EGR valve which might want checking isn't sticking?

Does the engine light flash on and go off when starting the car?

Emissions mot issue

Posted: Wed Apr 26, 2023 2:18 pm
by Wellhappy
Ah right ok 👍 thank you, I was scratching my head a bit tbh lol 😂 flushing the fuel again, but yep think a long run out somehow which is technically difficult lol as need the mot but to get the mot need to run it more .. thanks I will check the lights

Emissions mot issue

Posted: Wed Apr 26, 2023 2:19 pm
by Wellhappy
Scott560 wrote:
Wed Apr 26, 2023 2:15 pm
Once you have fixed any leak in the exhaust, it will take a while (and multiple restarts) for the engine fueling to be trimmed down. It's not always an instant thing, especially if the lambda sensor is tired or if the car hasn't driven much since the fix.

Not sure if the 2.0 has an EGR valve which might want checking isn't sticking?

Does the engine light flash on and go off when starting the car?
no they don’t flash fella ?

Emissions mot issue

Posted: Wed Apr 26, 2023 3:26 pm
by Scott560
I mean does it come on at all? The light should come on and go off when the car is turned on and started. This is to confirm the bulb is working.

If the bulb is faulty or has been removed - you will not know if the engine management light is on or not.