[mwebb]

071 is not a misfire DTc in OBD2
when you do set a misfire DTC in an OBD 2 system
in most systems
first you get a
P0300 which is random misfire , the system has detetcted misfire but is not sure which cylinder set the DTC
then
you get
P030X where X = the #of the misfiring cylinder

then
Mode6 testing is Disabled for Cat converter and 02 sensors

so your actual self induced DTCs number a minimum of 2
assuming not a speed density system

with those 2 DTCs testing is suspended for additional components

fuel trim will be affected by the 02 now present in the exhaust stream , system will appear lean , Mr Computer will attempt to get the 02 sensor s cycling again by adding fuel , LTFT will peg at it's upper limit and

you will set a DTC for
lean condition on the bank you have tampered with and the cat will have to deal with the extra UNneeded fuel present in the exhaust stream

which when added to the extra 02 will combust IN THE CAT. rendering it useless .

or the system may go to open loop , ign timing is retarded power reduced
Fuel economy does not and can not be "improving" as this unfolds
and it goes on ...

your understanding of how OBD2 system s function is
lacking

but
have no fear -
i will be happy to educate your self

your scenario of your own system's function and condition is
not plausible

try again - stop fibbing
i eagerly await your reply ....

thank me very much

Originally Posted by Heihetech

mwebb, to tell you the truth, nothing you mentioned has happened on my
DCD test vehicle over 3 years. I try to clear the OBD-II code once a month,
every time it shows "071"="misfire", no other real trouble generated. It all
depend on how the ECU is programmed to process the troubles. Many DCD
installed vehicles in China even never report "misfire". So it all depend on the
regulation and the related ECU software ----- a man-made issue.

By the way, how do you know the cat converter have already killed??? By
un-burnt fuel??? NO! This does not belong to DCD. DCD will stop injection
for some time, how does un-brunt fuel go into cat converter??? Or killed by
cool bypass air??? YES! DCD does have lot of bypassing air, but every vehicle
has such action when driver releases gas pedal during deceleration.