mattn32

Hi all, I'm a new Subaru owner with a bit of a problem. I've searched previous posts but have found no reference to what I've seen happening. Car is a MY99 Forester S-turbo, and has a bad flat spot between 2k-4k rpm. After searching the site I performed a ecu diagnostic check (which was clear) and reset the ECU. This hasn't helped matters, but curiously if I drive with the black diagnostic plugs connected, the flat spot is cured, and the car flies as it should. Disconnect them and it is back to square 1.

Firstly, does anyone have any idea what is going on? and secondly, will I do any damage driving with the black plugs connected and the check engine light flashing? (it's flashing the OK signal)

Thanks in advance for any help,
Matt

Butty

iTrader: (2)

Matt,
Can't see why just the black plugs treick works- thats only for reading the fault codes. If the green ones were also connected then the max boost is cut to something like 0.5 bar whilst the ECU is relearning.

I tend to get poor running at about those revs when the plugs are getting a bit worn, so I haul them out and regap every 7,500 miles or replace them every 15,000 miles.
I think that there is a general splutter in the fuelling anyway due to the ECU mapping, as its expecting a bit more Octane rating than even Optimax can deliver.

Nick
1997 Forester S/tb