NCT fail again for the 2nd time..

thegame · 10-11-2010 10:21am #1

Nct failed on the 1st attempt

Failed on Exhaust Leaking and 1 tyre 6yrs old

So got a brand new exhaust fitted and a new tyre..

2nd attempt at NCT..it failed on Exhaust Emissions

it failed on High Idle Lambda 1.04 limits were 0.97 and 1.03

does my car need to be checked out or does anyone know why this has happened??

its a 96 Honda Civic

Nissan doctor · 10-11-2010 10:33am

With the reading being such a tiny amount over I doubt its any problem with the exhaust or lambda etc. At 0.01 over the limit they are just being the usual NCT money grabbers. Allowing the car to warm up a little more or adjusting the test rpm by a couple of hundred would have brought it under I recon.

New exhaust need a bit of driving to fully carbonise and function correctly. Also if the car was not fully up to temperature when the test was done(maybe you only live/work a short distance from the center) that could also cause it.

Imo, book a retest, take the car for a good long drive before you bring it back and you should be fine.

biko · 10-11-2010 11:32am

Yup, just take it down the motorway for 20 mins before test, driving a 4500rpm or so (100kph in 4th gear). That should get it nice and hot.

Lambda refers to the air fuel ratio. Too high a lambda reading relates to too much oxygen. Too low a reading relates to too much fuel.

thegame · 11-11-2010 12:53pm

The Tester said he tried warming up the car but it was nt going down..it took me 45 mins to get to deansgrange for the test..its not off by much so before the retest ill rev it for a while and take it for a long spin..

DublinDilbert · 11-11-2010 12:57pm

Did they test the Emissions during the first test? What did the first fail sheet say?

They probably didn't do the Emissions test during the first test if the exhaust had holes in it. So this is the first time they are being tested. It could even be as simple as a small leak in the new exhaust system.

thegame · 11-11-2010 1:17pm

no they didnt test it the 1st time i was there..im going to go back to fastfit and get them have a quick look at the exhaust before i go back for the retest just to make sure and i have a 1yr free warranty on the exhaust anyway..

biko · 11-11-2010 1:19pm

This is a guess but it could be a leaking connection when they installed new exhaust or maybe there's a small hole somewhere before the lambda.
The mechanic should be able to sort it.

2 stroke · 11-11-2010 11:02pm

What oil temp do they show. I always drive to a test in a gear lower than I normally drive in. On a cold day it can be quite difficult to get the oil warm. I took a fiesta in last year that was drinking oil, it passed on emmisions, oil temp was 88 degrees.

thegame · 25-11-2010 2:15pm

Have the retest on sunday got my exhaust checked out and there is no problem with it.didn't get s emissions test may just try my luck and go down on sunday.

customer · 19-12-2010 1:18pm

My wife's car failed on high lambda (1.08 when range is 0.97 to 1.03). I heard that since HC and CO were ok, it might be air leaking INTO the exhaust path. I had a look under the car just after starting it and noted water drips from a couple of the joints (I'd taken the exhaust off to weld it earlier in the year and was too half-assed putting it back on)

I disassembled each joint, smeared gungum on each face, bolted them back together, put halfords repair fabric over that and stainless steel tape over that. Didn't look pretty but the tester won't see it if he's only retesting for emissions. On the retest, lambda was back down to 1.01

NCT fail again for the 2nd time..

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