Resetting Stock Ecu?

[myRB25DETT]

hey guys...

pardon my ignorance, but what does resetting ur stock ecu do??

does it actually make ur car more efficient or something??

please help the noob here!!

cheers

ps.still new to these turbo stuff...

[mad082]

this really depends on the ECU. most stock ecu's these days have a self learn function (some have 2) and resetting the clears these and puts the mapping back to the way it came from the factory. i think it can also sometimes clear fault codes, but this isn't always a good thing unless you are resetting it via a consult cable and have read the fault codes first.

my understanding (and what i have been told by mechanics) is that the self learn function remembers your driving style and alters the settings ever so slightly. so if you drive like an old lady all the time it would learn this and give you better fuel economy, etc. if you drive at 100% throttle everywhere it will add in a bit extra fuel to make sure it isn't going to lean out, etc. this can have an effect on your fuel economy if you buy a car from someone who drove it hard and then you start driving like an old lady. the 2 self learn systems are a long term and short term memory. the long term calculates an average from when the ecu was last reset and the short term is obviously a shorter period of time, but i'm not sure it if is just since the car was turned on last or if it is the past few trips. but an average of the 2 are then used to slightly influence the ignition and injector settings, especially for light load/cruise where it is in closed loop and is reading off the o2 sensor.

so if you just bought a car it could be worth resetting it, or if you get poor fuel economy no matter how you drive it might be worth resetting it, or if you have done major mods (such as fitting a full exhaust or changing boost levels, etc). if you have reset it in the past and haven't changed your driving style or done any mods to the car then there is no point doing it. i know people who have gained 10 to 20% better fuel economy by doing it.