| Just a bit of feedback concerning my original question...
[from the Sunday Times, Eric Dymock - ages ago]
"The converter is a stainless steel box, about a foot long,
in the exhaust system. It is known as a three-way converter
because it converts 90% of the three main pollutants -
carbon monoxide, acidic nitrogen oxides and hydrocarbons -
to relatively harmless carbon dioxide, water and nitrogen.
It does so by chemical catalytic action in a ceramic
honeycomb coated with the only metals that will do the
job.
"These are platinum and rhodium, which is why the cost of
the canister alone is �100-�370, depending on size. The
precious metals form a layer one molecule thick over an area
the size of two football pitches on the inside of the filter,
which lasts from 50,000 to 100,000 miles. Sensitive engine
management systems monitor the exhaust gases and adjust
fuel-injection and ignition systems to reduce contaminants.
"Amendments to British construction and use regulations
will require catalytic convertors to be inspected and maintained.
They affect performance and fuel consumption (top speed drops
by 2-3 mph, mpg by 2%), and need to be replaced when they wear
out. It will be an offence to drive a car without a
certificate to prove the emission-control equipment is
working efficiently."
John D.
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