I was at a meet recently at a shop, and I heard that if given enough time, the stock ECU can learn its way around the flash. That eventually the parameters changed by the flash would be returned to the stock values if left alone for like a year or two. He was saying that this explains why those with a flash just all the sudden have stuff go wrong for no apparent reason.

Now I personally think he's talking out of his ***, but I don't have a flash so I can't say, I'm just curious to here the responses to this... Fire away!

 

I understand the thinking behind that theory but I still dont think its possible. If that were the case, the ecu could also change parameters of the stock map and Mitsu wouldnt allow that. That would make it able to start running different mixtures on its own away from the stock map which would make the emissions results change. The ECU isnt smart enough to know what is a good mixture on its own. It goes by what its initially programmed as to where its supposed to be and then makes minor adjustsments as you drive to try to keep it where its programmed to be.

Hopefully this makes sense. Its kinda hard to put into words.

 

Nah, the parameters are the baseline map set.. When you modify the flash, you alter that baseline also. So it wouldn't just go back to stock.

Given bad gas, or other issues, the ECU could switch to a high detonation map which is typically less aggressive in tuning, or depending on who reflashed the ECU, the high detonation map could be totally stock and in turn, could run like the old stock map. But in reality, the good gas map is what is programmed, whether its stock or reflashed.. It won't "Rewrite" itself in any way perminently to go back to stock.

 

Yeah pretty much what I figured. I heard that and I was like "WHA??"

 

think i heard something about the ecu re-learning based on the info it gets form the sensors- somebody told me that if you disconnect the negative battery connector for 30 seconds or so you may be able to get a little more power after you reconnect it- something to do with the ecu re-learning the new info from the sensors, but dont know how true that is... I thought the factory ecu had certain factory set a/f ratios and that it wouldnt increase fuel to compensate for increased air flow/exhaust flow... hence the reason for a flash. But once flashed it does get rid of the stock settings and replace them with a new map- no way for it to revert or learn its way back to stock after the flash

 

The ECU will "learn" some parameters after it has been unplugged. Most notable is idle control. The whole process takes about 15 minutes on the VIII ECU, IIRC. It will not reset parameters within its standard map, though.

l8r)