Originally Posted by anthonyreading

First thing to do, and its free do the following:

Depending on what Impreza you have, there is a procedure which will allow you to reset the ECU in about a minute.

As said they are under the dash near your left knee when in the drivers seat.. follow the column down.. they are usually taped back with blue tape.. you will also see a bigger yellow connector for the select monitor..

ECU Reset

On early MYs (especially pre MY97) the ECU retards the ignition when knock is detected, however, it is very slow to advance the timing again. An ECU reset will restore the car to factory default settings. This will remove any stored fault codes and restore ignition advance. It is possible to reset the ECU by following these steps:

* Turn ignition OFF

* Connect Read Memory Connectors & Test Mode Connectors
(jumper 5) [black connectors] – (jumper 6) [green connectors]

* Turn ignition ON (engine off)

* Engine Check 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

* Code is indicated by Pulsing lamp

* If a fault is detected - Check ECU Code

* If no fault is detected - drive the car sensible for a couple of minutes
i.e. until warm (do not run tall & do not thrash it!)

* When the ECU has been reset the Check Engine Light will flash

* Code is indicated by Pulsing lamp

* If a fault is detected Check ECU Code

* Turn ignition OFF & Disconnect Connectors

* If there is a fault Check Appropriate Sensor
Check engine light error code is indicated by Pulsing lamp


If an error is detected then Check the ECU Code

If no error is detected - drive the car sensible for a couple of minutes
i.e. until warm (do not use boost or high rpm!)

When the ECU has been reset the Check Engine Light will flash

An Error Code is indicated by a flashing check engine light
of varying length of flash,
a flash of around once a second is the okay code and indicates all is well.

If an error code is detected Check the ECU Code

Turn ignition OFF and Disconnect Connectors

If there is a fault Check the Appropriate Sensor
Error Codes
An Error code is defined as a slow flash followed by fast flash
i.e 2 slow and 3 fast = 23 Mass Airflow sensor.
A continuous on/off at the same speed is no fault found.
Code Fault
11 Crankshaft position sensor

12 Starter switch

13 Camshaft position sensor

21 Engine coolant temperature sensor

22 Knock sensor

23 Mass air flow sensor

24 Idle air control solenoid

31 Throttle position sensor

32 Oxygen sensor

33 Vehicle speed sensor 2

35 Purge control solenoid valve

42 Idle switch

44 Wastegate control solenoid valve

45 Pressure sensor / Pressure exchange solenoid valve


In my case the speedo cable had snaped and the ecu picked it up and put me in limpmode at 3000 rpm

give it a try, could save you a few pennys

Originally Posted by kingogings

I`ve changed the maf sensor with a 2nd hand one , still the same?
New plugs , And 4x new coil packs ,

When driving if u dont boot it , she runs sort of better ,
but when u floor her up the gears from about 3 grand plus
starts 2 miss and backfire a little - then clears (ish)
on idle she seams fine..

sould i take her to the garage to get plugged in??

PS how do u no if its boasting rite??
I havent a clue - first turbo car!!