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As per title, wifes car has just failed its MOT (ireland) on emissions and i am wondering best course of action to fix it. Its a 1.4 petrol nissan note 2007, used for short runs mainly (school/shops etc). The emissions it failed was CO 0.35% and needs to be under 0.20%.
Is it a new catalytic converter, service or an Italian tune up. The engine was warmed up for the test as its a 20km drive to the test centre.
Any suggestion
Thanks in advance
What did the tester suggest?
A service and Italian tune up isn't going to hurt, nor is wynns emissions reducer. Worth a try before replacing a Cat
I asked similar question a couple of years back, but for a car that hadn;t run for a couple of years.
Could be worth a bit of an italian tune up, but also a full service if it hasn;t been done recently. I'm sure on one of the wheeler dealer episodes, Ed shows how a basic service (oil, filters, plugs etc) can make quite a difference to emmisions
https://singletrackmag.com/forum/topic/mot-for-a-car-thats-not-run-in-over-1-year/
New plugs air filter some fuel treatment n give it some pain. It'll go through.
An oil change too wouldn't go amiss
Take the airfilter out, that'll get the emissions down a bit if you just want to get it through the Mot. But getting it serviced and tuned properly is what you should be doing.
Similar issue for our Golf, last month.
A bit of motorway driving and a good run down a clear A road sorted it and it passed the emissions on a re-check.
Whilst investigating, I came across an odd contribution to poor emissions - some engines have a temperature controlled flap to pull air from over the exhaust manifold for cold start/cold conditions and air from "another place", when warm.
The actuator can stop working and stick in the cold position, so it pulls in very hot air during the emissions test and it is not linked to the ecu so no fault is reported.
On the Golf, the actuator is buried in the big black air box, on top of the engine.
if the oil has not been changed it will be contaminated with fuel , this evaporates into the breather system and manifests itself as extra non metered fuel (petrol) as well as oil/water vapou mix , this has most impact at idle and will easily push over the limit, the fact that it is near the limit means there is no big fault, so change the oil and go for a good run 50 miles is better.
If you have already changed the oil then it could still be residue in the breather system.
Change the oil if it's overdue.
Put some injector cleaner through it.
Consider new spark plugs and air filter.
None of these will make it drive any worse or less reliably, nor will they break the bank, so maybe just do them all anyway.
Thanks everyone. The tester didnt really suggest anything to my wife so good to hear your opinions. The car doesnt do much milage and is due a service if i am honest, i think its nearly 2 years since its last one so i guess we will start there.
And i have just heard apparently she was nearly out of fuel doing the test (my wife never had time to fill it up like she was meant to) which probably didnt help either.
A bottle of injector cleaner & a bottle of catalyst cleaner got my subaru through the emissions test.
To be honest the best thing you can do is throw some injector cleaner in the fuel then take it for a decent 20 mile razz up the motorway and get the temps nice and high, keep it in 4th rather than 5th and you should hopefully burn off a load of crap in the engine thats built upwhilst pottering about locally.
Oil and filter change next. When you take it for its retest, take the long way there and give it a good thrashing on the way and get it tested whilst its still warm.
Take the airfilter out, that’ll get the emissions down a bit i
will it chuff. all it'll do is maybe let some dust into the engine. injection engines monitor the amount of air being fed in and feed the exact right amount of fuel. Spark plugs are most likely to make a difference on the cheap, along with an italian tune-up. Check the fault codes that none of the sensors are on the duff causing it to run as an open circuit as well
def a service. Did it fail on anything else as you can potentially get excess lubricant burn if the piston seals have gone, though not terminal as sometimes they just need a run. This can manifest in excess CO, but you'll also get excessive soot generation which would be a fail.
As you're in Ireland, the fuel quality can be a bit shitty at times, get a tank of a well known brand in the tank (the Nitro/Excellium eqv., you don't need a "wynnes" or "redex" as it's the same stuff) as it will help with the fuel system, both Inlet valve deposits as well as injector fouling. Clean filters, both fuel and air are always good. Bit of a thrash then re-check.
the Nitro/Excellium eqv., you don’t need a “wynnes” or “redex” as it’s the same stuff
Can cost more than a cheap tank of petrol plus redex though.
the car passed on everything else but the emissions and each retest is €30, so want to just get it through. My wife got some fuel additive to run through the tank before it goes in for a service on monday and its retest is booked for next friday. Fingers crossed, will update the outcome.
philjunior
Member
the Nitro/Excellium eqv., you don’t need a “wynnes” or “redex” as it’s the same stuffCan cost more than a cheap tank of petrol plus redex though
I agree, but knowing that Ireland has massive issues with fuel fraud and it being a dumping ground for some nasties, it's better to keep with the more well known brands as the control is better.
UPDATE.
So we put the fuel additive in and gave it an Italian tune up and also a service and..........it passed.
Cheers.