sw_hunt

...commonly known as Scooby's droop.

Apologies if you all know about this one but it was news to me, so...

I had to fill up the P1 for the first time with ordinary petrol and it was slow. Fair enough. Put some octane booster in and it was a bit better. Filled up with a couple of tanks of Super, but the performance was never as good as before and it felt quite rough. After some research I learnt about the old 'reset ECU trick'.
Apparently what happens is the ECU compensates for the lower octane fuel by retarding the ignition and lowering the boost. BUT... when you fill up with decent petrol it never winds up the boost again...or rather it does eventually but it takes many many tanks to average out.
So what you do is disconnect the battery (I did it overnight but I don't know how long it takes...just be careful you park it in a garage because the alarm might not be powered) and just connect it back up in the morning. The ECU will have forgotten it's settings and start again from fresh.
Back to full power again and smooth as a ...well as smooth as a P1 gets anyway!

cryptwalk

Or do this.........

Connect Test Mode & Read Memory connectors (jumper 6&5) [green & black]
Turn ignition ON (engine off)
Malfunction indicator lamp turns on
Depress accelerator pedal completely
Then return it to the half-throttle position and hold it there for two seconds
Release pedal completely
Start engine
Trouble code is indicated on malfunction lamp
(If code = OK code then turn ignition off and disconnect test mode wire)
Comfirm trouble code
If no trouble code is indicated, drive over 11 Km/h for more than 2 minutes until engine warm
Trouble code is indicated on malfunction lamp
Turn ignition OFF
Disconnect Test Mode & Read Memory connectors

Tiggs

what?

park it in the garage then with no battery!

Tiggs

mhawes

Does it make a lot of difference then as I tried a tank of super last week in my uk MY95 and didnt notice a bit of difference but will I notice the difference if I reset the ECU?

Sith

Early cars take a month of Sundays to learn and adjust.

P.

stevencotton

My MY98 went in for a service a couple of weeks ago so I asked them (Subaru dealership) to perform the ECU reset, cost me £15 on top. I noticed a slight improvement on mid-range acceleration but the change wasn't significant. I think it depends on the car, some cars will get a massive improvement, some wont.

Steve.