Nearly 40% of the air intake area is a marginal restriction?
NOX emissions are not part of the MOT test on diesel vehicles it is purely a smoke test.(but by the way my tester stated that mine had the cleanest emissions he'd seen in along time)
Fact: Egr systems reduce NOX emissions at the expense of power and fuel ecomony.
They are there to try and reduce emissions, they are not essential for the running of the engine.
There are probably more harmful emissions caused by a malfuntioning valve (which is probably quite common) and poor servicing and maintenance, than the possible small increase in the use of the bypass. After all only 6-10% of the exhaust gases are recirculated the rest goes out of the tailpipe.
The cleanest engines are those that use fuel and air in the correct mix at the right time to enable complete combustion.
Many people who have fitted the bypass have also fitted one of Ron's tuning boxes, so the engine is not in it's original state of tune.
It would be interesting to know the NOX emissions from cars fitted with both for comparison but these days I don't have access to an anyliser.
One thing I can say for sure is the car revs more freely with it fitted and doesn't struggle to accelerate when required as it did before, and mpg has increased approx 3mpg which is about 8%. Which is also good for the my wallet and the environment.
Russ
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