NCT failure: emissions (nearly)

case_sensitive

Hi all,

I put the car through the NCT there, failing on some minor points that will be sorted this weekend (including failing to remove the wheel caps!).

However, more worryingly, it came *very* close to failing on more serious bits, I was wondering how fixed these thresholds were?

For instance, on low idle (840rpm) I scored CO: 0.49%, with failure listed as 0.50%.
HC was 210 ppm, but they've listed 'above 0ppm' as a failure (but not failed me??)

High idle lambda was 1.00 (sounds like cat isn't doing anything ), not between 0.97 - 1.03 listed as failure.

and finally, CO was 0.28% at high idle (2920rpm), with 0.30% failing.

Listed fail/refusals are for other bits, but in a year's time, I'll be looking at either a new cat (?), lambda sensor or other expensive parts by the looks.

Any ideas?

ZENER

case_sensitive wrote: »

For instance, on low idle (840rpm) I scored CO: 0.49%, with failure listed as 0.50%.

How old is the car ? On my cert anything above 0.3% is a fail ?

HC was 210 ppm, but they've listed 'above 0ppm' as a failure (but not failed me??)

I think this is again down to the age of the car. My cert says HC 15ppm but has N/A beside it.

High idle lambda was 1.00 (sounds like cat isn't doing anything ), not between 0.97 - 1.03 listed as failure.

Isn't 1.00 between 0.97 and 1.03 ?

and finally, CO was 0.28% at high idle (2920rpm), with 0.30% failing.

0.2% on my cert but again they are more lenient on older cars.

Listed fail/refusals are for other bits, but in a year's time, I'll be looking at either a new cat (?), lambda sensor or other expensive parts by the looks.

Maybe not but I'm sure the more knowledgeable here will let you know.

Ken

Nissan doctor

case_sensitive wrote: »

Hi all,

I put the car through the NCT there, failing on some minor points that will be sorted this weekend (including failing to remove the wheel caps!).

However, more worryingly, it came *very* close to failing on more serious bits, I was wondering how fixed these thresholds were?

For instance, on low idle (840rpm) I scored CO: 0.49%, with failure listed as 0.50%.
HC was 210 ppm, but they've listed 'above 0ppm' as a failure (but not failed me??)

High idle lambda was 1.00 (sounds like cat isn't doing anything ), not between 0.97 - 1.03 listed as failure.

and finally, CO was 0.28% at high idle (2920rpm), with 0.30% failing.

Listed fail/refusals are for other bits, but in a year's time, I'll be looking at either a new cat (?), lambda sensor or other expensive parts by the looks.

Any ideas?

Your lambda reading is a perfect as it can be.

The HC is not tested at low idle, hence not failing.

The CO's being so close to the limit could indicate a very slight exhaust leak.

case_sensitive

Yeah, the back box is definitely rusty, so there could be/almost certainly is some rusting further back.
From visual inspection the manifold to cat to mid section looks ok, but I haven't pulled it out, so it could be on the other side.
Might get a high-flow sports cat while I'm having the lot out sometime during the year, but nothing to get fret about for the next 13 months.