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Knock sensor troubles 93 liberty EJ22.

Posted: Thu Jul 07, 2011 2:02 pm
by freddo
G'day,

So I plugged my error code wires together the other day after some idling issues. When warm and sittin stationary for more than 30 sec, engine would drop the revs til almost stalling, then pick back up to around 1100 rpm, before dorrping down again etc...

Car did not have check engine light showing...

Code given was 22, 2 long flashes, 2 quick flashes. So I took it to subie for them to suss out what was wrong with the knock sensor, ie, was the sensor cracked, or was it another issue.

They told me faulty sensor, so I baught one off ebay ($90, partsden).

Fitted it this morning, and check engine light wont turn off, checked the codes again, and wouldn't you know it.. 22.

What to do?

Cheers, help appreciated,

Tim

Posted: Thu Jul 07, 2011 2:06 pm
by Venom
You could try resetting the ECU to clear the codes, theres are a few posts around on how to do that.

Posted: Thu Jul 07, 2011 2:26 pm
by freddo
I'm a little hesitant to wipe the code..

Or will the code come back if there is an ongoing problem with new knock sensor?

Also found out from Subie that head gaskets are Farked, but there isnt any oil in coolant, or vise versa... at this stage..

Is it a ticking time bomb till the engine overheats? I was planning on driving to the snow (with a spare bottle of oil and coolant) and back in a couple of weeks...

Bad Idea?

Anyone want to buy it? :) only has 150,000km, and its got a new knock sensor ;)

Posted: Thu Jul 07, 2011 2:34 pm
by niterida
Yeah you have to reset the ECU to clear the history but I'm pretty sure it shouldn't be showing check engine light if the sensor is working ok.

You either have a wiring fault, another faulty sensor (was it new or 2nd hand ?) or a very rattly engine ??

Posted: Thu Jul 07, 2011 5:15 pm
by freddo
yeah, it was a new knock sensor...

So I connected black-black, and green-green plugs..
turned ignition to on not starting
changed gear lever from P to N to P
full throttle on accellerator for a few seconds
back off throttle, start car
drive for a minute or more above 12kmph
And got a new fault code...

changed from 22 (knock sensor) to 47 which raven says in fuel injector, but this site http://www.troublecodes.net/Subaru/ says there shouldnt be a 47 for my "1988 and later models with Multi-Point Fuel Injection (including Legacy)"

any suggestions?