MOT Emissions Limits NB 1.8

Technical Area Engine, Transmission, Exhaust etc
1
  1. My model of MX-5 is: __,NB 1.8 year 2000
  2. I’m based near: __Stockport
  3. I’m looking for technical help or recommendations on: __CO Limits.

Failed on emissions for the MOT , only on CO doh :frowning:

I gave her some new sparks , air filter and a dose of cat cleaner in the tank and squeaked a pass second time around yay!

My question is, what are the actual limits for normal and fast idle for the 1.8 NB.

Vin code is NB18P2. If I look that up on the .gov website it has limits for CO of

0.5% on ide

0.3% on fast idle

See Vehicle exhaust emission standards - GOV.UK

In Service Exhaust Emission Standards for Road Vehicles Nineteenth Edition

The MOT states limits of 0.3 and 0.2% respectively.

Have I misunderstood or misread the .gov specs?

2

Mot tester has got it wrong. If it fails the basic emissions test, the tester must proceed to the extended emissions test referring to the annex.

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3

If it still fails, try setting the spark timing to 14 degrees advance. It’ll give the fuel/air mix a little more time to fully combust.

4

No need, passed after cat cleaner and new plugs on the 0.2/0.3% So happy days