[mwebb]

depending on the system ," misfire " detection by mr computer causes additional events to take place , not the least of which is suspended Mode 6 testing of various components - some systems will disable injectors on the misfiring cylinder , some will prevent the transaxle from shifting "normally" some will revert to open loop and retard ignition timing to limit max power output .
in other words

when your system detects misfire , everything changes , and NO this is not a desirable state or condition for your system to be in

you may have already killed your cat converter , but you will never know as your system can not test for it as testing is suspended by your tampering .

Originally Posted by Heihetech

That's right. OBD-II will report "mis-fire" when DCD IS ON. But this is only a
computer code, not a real engine trouble. It will not kill the engine, not kill
the driver and the vehicle. My DCD controlled vehicle has run over 3 years
without other problem. The code gives us the info "DCD runs OK!" and MIL
blinking means "DCD in Progress." The code can be cleared at any time easily
whenever you want, totally worry free.

So OBD-II code that makes trouble should be ignored, so as any related
comments and topics. EPA may not like this, but their software should be
modified accordingly to get rid of the "trouble" by code. DCD don't make
any trouble, but OBD-II code does. So please ignore it and stop talking it.