97 impreza- all 4 cylinders misfire

[Lala]

I have a 97 impreza outback, standard transmission, 113000K
The check engine light has been on for 3 months now with me fighting to
find the cause. The codes are and always has been misfires detected in
all 4 cylinders (a seperate code for each cylinder).
Already I have change plugs, wires, ignition coil (all subaru-brand
parts). Also the air filter and fuel filter just for fun! At this point
the light still kept coming back on. After I reset the CEL about the
3rd time, the light finally didnt come back on .... for 1000k.
I have since check my coolant to make sure it is still green...
suggesting that a blown head gasket is not the cause. I also checked
the female pin connector parts that connect to the ignition coil adn
they seem to fit snugly with the pins on the ig. coil.
The car runs great, even the subaru specialist I took it to said so!
You cant tell its misfiring...no loss of power, idles very quietly...
even when the light is flashing, and yes I know flashing is a bad
thing. The light flashes mostly when the cars is about 3000rpms at
70mph or at 3000rpms going up a hill... but every once in awhile it
choses to flash randomly, for example when I am idling at 500-700rmps
at a stop light.

Any other suggestions as to the cause? I do have slight oil leak from
somewhere. Oil just accumulates on a pan at the bottom of the engine
and burns off during long cars trips. Could this be causing misfires
somehow if the oil is getting in somewhere it is not supposed to? Why
would the light go out for 1000k and now be on all the time? And why
cant I tell in the performance of the car when all four cylinders are
misfiring?

I just want to cover the light with black electric tape

Thanks!
Lara

 

[Carl 1 Lucky Texan]

I have a 97 impreza outback, standard transmission, 113000K
The check engine light has been on for 3 months now with me fighting to
find the cause. The codes are and always has been misfires detected in
all 4 cylinders (a seperate code for each cylinder).
Already I have change plugs, wires, ignition coil (all subaru-brand
parts). Also the air filter and fuel filter just for fun! At this point
the light still kept coming back on. After I reset the CEL about the
3rd time, the light finally didnt come back on .... for 1000k.
I have since check my coolant to make sure it is still green...
suggesting that a blown head gasket is not the cause. I also checked
the female pin connector parts that connect to the ignition coil adn
they seem to fit snugly with the pins on the ig. coil.
The car runs great, even the subaru specialist I took it to said so!
You cant tell its misfiring...no loss of power, idles very quietly...
even when the light is flashing, and yes I know flashing is a bad
thing. The light flashes mostly when the cars is about 3000rpms at
70mph or at 3000rpms going up a hill... but every once in awhile it
choses to flash randomly, for example when I am idling at 500-700rmps
at a stop light.

Any other suggestions as to the cause? I do have slight oil leak from
somewhere. Oil just accumulates on a pan at the bottom of the engine
and burns off during long cars trips. Could this be causing misfires
somehow if the oil is getting in somewhere it is not supposed to? Why
would the light go out for 1000k and now be on all the time? And why
cant I tell in the performance of the car when all four cylinders are
misfiring?

I just want to cover the light with black electric tape

Thanks!
Lara

 

[w.milaan]

Good morning,

Check if the earthing of the engine and the ECU are good.
Check the wiring between the Engine and the ECU.
There are a lot of connection on the left side of the enginebay .
(located near the gearbox oil stick)
And you can always check the connections of the ECU.(located
at the passenger feet).
Newer cars can have a lot of problems with wiring.
The ECU depends on proper signals.

Gr. Walter