NCT Fail - Emmissions

dougie ward

anyone know what engine cleaner is out there to reduce emmissions?
a mate said to rev the hell out of it before the nct to clean it a bit,does this work? dont want to spend a fortune on it,want to pass the NCT and sell it asap.

Thanks

Captain Slow IRL

There are a few different types of fuel cleaner out there, but don't expect miracles from them. I tested Dipethane before my nct and it only lowered the CO by 0.02%, so in the short term it didn't do very much.

"Revving the hell out of it" does very similiar to the fuel cleaner - if you have a faulty catalytic convertor or exhaust/engine fault, this won't fix it.

If this is all you failed on, book into your local garage for an emission check. Try and get about a half hour of driving before the check to heat the engine up. Get the car onto a main road, get upto 100kmph and don't go past 3rd gear. It shouldn't take long, just a minute or 3 to clear the exhaust out.

Good luck!

dougie ward

thanks Captain, the emissions are a bit on the high side if that only takes it down by 0.02 then its off to the garage!

LookBehindYou

is it Petrol or Diesel ?

AzureAuto

Revving the hell out of it wont clear out faulty injectors, or remove gunk from a clogged up breather pcv pipe or shift deposits off an old CAT, but what it will do is raise the engine temp to the optimum before the test. Interestingly, a lot of the cars I have sent for NCT have only been tested when oil temp is around 88-95 degrees. Fine for newer cars with nice new lambda sensors, but when you've an older car with a sensor that maybe getting a bit sluggish, this can prove the difference between a pass and a fail. If the test comes back to you with a fail, and the test paper says the oil temp is lower than 100 degrees, outright refuse to accept it and demand that the car be test at a higher temp, they are obliged to do so.
And on the subject of fuel injector cleaners...its a racket, i have noticed very little difference in performance or emissions after using them. Use good quality fuel in the first place, replace your fuel filter at the recommended intervals, or if you are having injector issues, have them ultrasonically cleaned.
Now Im off for breakfast..best of luck with your retest.

Cosmo K

AzureAuto wrote: »

Revving the hell out of it wont clear out faulty injectors, or remove gunk from a clogged up breather pcv pipe or shift deposits off an old CAT, but what it will do is raise the engine temp to the optimum before the test. Interestingly, a lot of the cars I have sent for NCT have only been tested when oil temp is around 88-95 degrees. Fine for newer cars with nice new lambda sensors, but when you've an older car with a sensor that maybe getting a bit sluggish, this can prove the difference between a pass and a fail. If the test comes back to you with a fail, and the test paper says the oil temp is lower than 100 degrees, outright refuse to accept it and demand that the car be test at a higher temp, they are obliged to do so.
And on the subject of fuel injector cleaners...its a racket, i have noticed very little difference in performance or emissions after using them. Use good quality fuel in the first place, replace your fuel filter at the recommended intervals, or if you are having injector issues, have them ultrasonically cleaned.
Now Im off for breakfast..best of luck with your retest.

Sorry, but you are completely wrong! Telling someone, to demand a Re-test, simply because the engine temperature is below 100 degrees, is bad advice. Limit for engine temp is 80 degrees, once the temp is over 80 degrees, I don't have to give the customer a free Re-test.

I have no problem, doing the emissions test again, if the car is only slightly over the limit, lets say, CO is 0.54, so its only 0.04% over the limit, in such a case, I would definitley repeat the test.

But if CO is way over the limit (basically anything above 1.0%), and the engine temp was over 80 degrees for the test, I would not repeat the test, waste of time.

dougie ward

emision was over 2.0 so it defo needs to go to garage i think, its a petrol pajero junior, what you guys reckon the prob? cat convertor? dont want to spend a fortune but of course it needs to pass the test for resale and if i want to drive it!

ToxicPaddy

My last car failed the NCT by .5% on emissions so I gave up on it, should have tried that cleaner Dipethane, then I would still have it..

Typical eh?

moceri

New spark plugs and air filter did the trick for me

cnocbui

Cosmo K wrote: »

Sorry, but you are completely wrong! Telling someone, to demand a Re-test, simply because the engine temperature is below 100 degrees, is bad advice. Limit for engine temp is 80 degrees, once the temp is over 80 degrees, I don't have to give the customer a free Re-test.

He said OIL temperature. If you think that is the same as engine coolant temp...

Lucifer

He did mean oil temperature. By the sounds of it he is an NCT tester so I will assume he knows what he is talking about. If you have a look at the NCT report there will be a figure for oil temp, not coolant temp, which is measured at the time of the emissions test.

Cosmo K

Lucifer wrote: »

If you have a look at the NCT report there will be a figure for oil temp, not coolant temp, which is measured at the time of the emissions test.

Actually, it says engine/oil temperature.

cloneslad

I failed my retest on the emissions yesterday (failed it the 1st time on a few things, got those fixed up and then they did the emissions test yesterday cos they couldn't do it first time round) Anyway, I was allowed to be 1.03 but my reading was 1.058 or so. Brought it to the mechanic who fixed everything up for me, he told me to buy all the stuff for a service (oil, plugs, filter etc) and he did the service for free (the stuff cost me €30) He also put a clamp on the exhaust for me too.

I also bought a bottle of some sort of petrol cleaning thing too ( it came in a red bottle) Anyway went back in for my re-retest :rolleyes: today and the reading was 1.026 which was 0.004 under the limit.

It was like watching my first child doing their leaving cert (if I had a kid, or was over 25) when I was looking at the guys doing the emmissions test, felt sick to my stomach for fear of failing again.

So, these things worked for me to get my reading down. by the way I have a 1.4 petrol Peugeot 206