Some further information
According to my MOT test, which only looks at idle.
CO: 0.83% measured (limit is 3.5% for this 95 year of car)
HC: 103ppm measured (limit is 1200ppm for this 95 year)
Euro 4 petrol limit needed for ULEZ is
CO: 1g/km
HC: 0.1g/km
NOx: 0.08
(Euro 5+6 are not much different for petrol)
A 1997 car should Euro 2 I think
Euro 2 limits are:
CO:2.2g/km
HC+NOx=0.5g/km
Presumably this is while running a WLTP cycle, so that can be expensive to use a lab to certify this.
The problems tuners will have is they will probably not be able to accumulate emissions or measure total output, they can only measure ppm.
While my results from the redblock are very good idle, this is easy to achieve, the reality of unpredictable loads and slow response sensors is very different. Modern cars use MAP (manifold pressure) to measure load more quickly than MAF (airflow) and you can certainly upgrade to this, maybe improve efficiency with wideband lambda, but its still going to be hit and miss if you can meet the standards.
Anything is possible with enough money, but you could be looking at £100K to do the development work and fine tune the engine management, just to fix a small issue at some point in the load band.
|