Wasn't too sure about the old ECU reset argument, but it works. I bought some millers octane booster for my Sti 3 V-ltd and thought i may as well go the full hog and disconnect the battery for a couple of hours. Took her out for a spin to recalibrate the beast and it was definately much smoother and had much more umph! at higher revs. Cool, I always run her on SUL and i realise that the millers will improve the performance but the reset has definately made that process much more instant and thus more noticeable.

I also had the opportunity to slap a nissan 200sx driver into the floor as he was driving like a Tos#@r and he tried to pass me and another car at the same time just as we approached a 1 mile long hill on a straight road(need i say more).
lol

cheers scott

 

Recently I was forced to put in a few pounds of premium instead of super, so i filled up with super as soon as i could, and disconected the battery overnight, when it was well below 0 degrees! I have no idea if it worked (although no booster was used)
I thought that certain capacitors in the ECU have to be drained before the relevent bit of its memory is wiped? surely disconecting the battery would just break the circuit and not drain these?

 

!!!!!!!!!!!
Word of warning to anyone doing the ECU reset, if you have a radio that has a code make sure that you know the code.
I made that mistake, I never knew a code was needed until I disconnected the battery. When I connected it back up.. Code ???.
I was fortunate enough that my girlfriend treated me to a new CD/Radio Head unit, when I went to fit it I removed the old stereo and written on the side was the code. I sold it to a mate and never told my girlfriend .

Why don't you do the ECU reset by using the conenctors as described on :

 

The radio probably also seemed louder and faster too!

I tried a reset on mine last year, after putting SUL in the last two tanks. Nothing measurable.

Anyone with one of these fancy timing meters care to report their findings?

regards,
Rob.

 

What about the radio settings after the battery has been disconnected?

 

Have done the same with mine on Friday night, left the battery disconnected for about 20hrs. Not exactly sure if it has made alot of difference yet (using SUL before and after). More than anything I am hoping that the fuel economy will improve, with performance increase as a bonus!

There is another method for resetting the ecu, see the thread 'Unleaded vs Super Unleaded'. It is the MRT rally method, but I have not tried it yet.

 

ECU reset has different effects dependant on MY of car. On MY99/00 its a waste of time as the ecu is constantly updating itself. On earlier cars it can have an effect but ... if the car was ok and the ecu was at nominal then you will notice very little difference. Fron UL to SUL it will have an effect but even the early ecu's will adapt eventually and they could drag it down again if things were not happy. Its not a permanent thing, it's effect is valid as long as favourable conditions and fuel are used, one bad tank and it will revert.