Quote:
Originally Posted by Frank Lee
What do you guys think might happen? The thing is basically an artificial limp home mode...
|
Well, the onboard engine misfire monitor would notice incorrect crankshaft angular accelerations/decelerations from intentionally shutting off cylinders in the pattern that
heihetech suggests. That would throw a P0300 DTC (multiple engine misfires detected), cause the CEL to turn on, and would cause the engine to go into open-loop mode. The engine would go into open-loop mode because the engine computer programming would assume that O2 sensor output is flat-out no longer reliable due to the existence of repeating randomly misfiring cylinders, so it doesn't even matter whether or not
heihetech's magic black box has a WBO2 sensor with narrowband output to the engine computer.
Since the engine computer would not know any better, it would then assume that the shut-off cylinders were exhausting unburnt fuel into the catalytic converter(s). Assuming this, the engine computer would cause the CEL to start blinking, and would go into limp-in mode to lower engine power in an attempt to mitigate assumed possible catalytic converter damage. This would cause ignition timing to be retarded, which would cause engine efficiency to be lowered.
It's possible, but not very likely, that physical engine damage (broken crank or conrods) may occur, due to the unbalanced nature of an intentionally misfiring engine.