Extremely low emissions in MOT - why?

[colesl4w]

Hi all,

Not that I'm complaining about low emissions at all, but just carious as to why this would happen! I was getting my 05 Z MOT'd last week, and during the emissions test I had 2 or 3 testers standing around their machine scratching their head wondering why my emissions were so low. They made me rev the engine a few times just to get something detected. To be honest I initially thought I was way over the emissions as one tester said "oh dear oh dear oh dear" out loud lol. The car has nearly 90k miles on it, standard cats, but a very new Ark Grip fitted.

 

Can anyone explain why my emissions would be so low as to cause the testers confusion? I'm guessing the new exhaust might be something to do with it?

[veeg33]

Oh no......have you just uncovered another embedded software in Nissan?

 

I'm not sure why, could be your new exhaust as you mentioned or their machine. How many miles have you driven with the ARK fitted?

[colesl4w]

Oh no......have you just uncovered another embedded software in Nissan?

 

I'm not sure why, could be your new exhaust as you mentioned or their machine. How many miles have you driven with the ARK fitted?

 

Hahah, I'd say the grip had about 1.5k miles on it at the time of testing.

[Zeezeebaba]

My last MOT I had the same issue 05 DE with new Berk and Miltek. During the Uprev map a month or so later I was told the car was running really lean. It's not anymore so next MOT will be different.

[veeg33]

Maybe the ARK has great filtration system? which i don't think so.....Go back to the same MOT station next year and compare the readings.

Edited April 21, 2016 by veeg33

[Ekona]

There are some things in life I worry about. There are other things that I don't.

 

Having emissions that are exceptionally good on an MOT would go into the latter camp, and would never be thought about again.

[colesl4w]

There are some things in life I worry about. There are other things that I don't.

 

Having emissions that are exceptionally good on an MOT would go into the latter camp, and would never be thought about again.

 

Hahah certainly not a worry, just more curiosity than anything!

 

Zeezeebaba makes a good point about maybe running lean. Something for me to consider looking into in the future!

[GreenLandy]

A new pipe makes no difference to what goes into it! (cats aside)

 

I'd guess it's running rather lean.

[KUGT4]

mines standard - also 90k - very low mot emissions also

 

makes a change from the last car i owned - needed a new cat every 2 years to get through the mot

[Jack wellZ]

I thought that when you change something e.g. Exhaust the Ecu will revert anyway so that it doesn't mess with it leaning out that's why you get everything done before mapping?