Nct Emissions Fail

pk10216

Put my honda civic vti 1999 through nct about two weeks ago. The car had no cat fitted (de-cat) I was sure it was going to fail on emissions but thought there would be a few other minor things to be done on it so got it tested.
Car passed on everything bar emissions,

DECAT

Low Idle - CO 0.61 vol% (ABOVE 0.50% FAIL) Result = FAIL
(980 RPM)

High Idle - Lambda : 1.01 (Not between 0.97 and 1.03 FAIL) Result = PASS
(2810 RPM) CO 0.85 vol% (ABOVE 0.30% FAIL) Result = FAIL
HC 141 ppm ( ABOVE 200PPM FAIL) Result = Pass


I then went and had a CAT fitted

and results were as follows

Low Idle - CO 0.72 vol% (ABOVE 0.50% FAIL) Result = FAIL
(980 RPM)

High Idle - Lambda : 0.99 (Not between 0.97 and 1.03 FAIL) Result = PASS
(2810 RPM) CO 0.49 vol% (ABOVE 0.30% FAIL) Result = FAIL
HC 51 ppm ( ABOVE 200PPM FAIL) Result = Pass

Really wasn't expecting it to fail, I mean the car de-cat was only just over the emissions surely the cat should have passed it ( low idle result has actually gone up since the cat was fitted!!!!). Any Ideas????

msg11

pk10216 wrote: »

Put my honda civic vti 1999 through nct about two weeks ago. The car had no cat fitted (de-cat) I was sure it was going to fail on emissions but thought there would be a few other minor things to be done on it so got it tested.
Car passed on everything bar emissions,

DECAT

Low Idle - CO 0.61 vol% (ABOVE 0.50% FAIL) Result = FAIL
(980 RPM)

High Idle - Lambda : 1.01 (Not between 0.97 and 1.03 FAIL) Result = PASS
(2810 RPM) CO 0.85 vol% (ABOVE 0.30% FAIL) Result = FAIL
HC 141 ppm ( ABOVE 200PPM FAIL) Result = Pass


I then went and had a CAT fitted

and results were as follows

Low Idle - CO 0.72 vol% (ABOVE 0.50% FAIL) Result = FAIL
(980 RPM)

High Idle - Lambda : 0.99 (Not between 0.97 and 1.03 FAIL) Result = PASS
(2810 RPM) CO 0.49 vol% (ABOVE 0.30% FAIL) Result = FAIL
HC 51 ppm ( ABOVE 200PPM FAIL) Result = Pass

Really wasn't expecting it to fail, I mean the car de-cat was only just over the emissions surely the cat should have passed it ( low idle result has actually gone up since the cat was fitted!!!!). Any Ideas????

Did they replace the seals? No expert on it but it could have a hole or it's taking in air somewhere along the exhaust.

If you want to pass mix some dipetane fuel additive into the car before the test. Also, try give the car a good run about before the test.

Chimaera

From looking at the results you posted, the cat is doing its job (CO and HC lower under load) but it's not a magic wand if there's something more fundamentally wrong with the fuelling.

Was the car well warmed up before the test? Cold engines don't perform well in emissions tests.

After that, I'm not sure - I'd probably have a chat with a mechanic who knows these cars and see what he thinks.

pk10216

Was was not given a long drive before hand, maybe 15 mins but it did give it a but of welly so cat should have been plenty hot. Gonna change spark plugs and add some fuel additive and try again maybe give it a good long drive before hand and good trashing. Cheers for the replys