Throttle Plate Control

[PATTEEUW at etcv01.eld.ford.com]

Todd Day said:

"The ECU is pretty anal about not fueling a non-sparking cylinder.  It
can determine when one of the drivers that controls the FETs that
control the coils fails and will let you limp along on two cylinders
while not fueling the other two cylinders."


True !

This is part of the OBD-II diagnostics that CA has forced on all manufacturers. 
One "misfiring" (incomplete combustion) can seriously reduce the efficiency of
a catalyst.  A few hundred to a few thousand miles can cause permanent damage
to the cat.  So if the ECU can determine that a cylinder is misfiring for any
reason (bad plug, wire, hung valve, etc.) then no fuel is allowed into the
cylinder and the "check engine light" goes on.


Jack