In DCD Control, fuel loop is closed by using a wideband oxygen sensor to
detect high-lambda area. So, if the engine has had lean-brun in it as you
mentioned, the fuel loop will be closed at even higher point.
There might be many good ideas or inventions in 1960s. Yet by that time
there was no computer, no ECU, NO CLOSED FUEL LOOP, no oxygen sensor,
any good idea was just a dream, hard to BE implemented. Nowadays we have
had everything include DCD, so that DCD product can be implemented, and
NICE DREAM OF DCD HAS BECOME TRUE!!!
The message I want to release here is that DCD is a pure elecronics solution,
except replacing oxygen sensor, there will be no mechanical work involved.
It is worth to try, easy to handle, and the result is your fuel savings, from
5% to 13% according to driving conditions (based on my tests on 4-cylinder
vehicle, 8-cylinder vehicle could save even more).
