04 GT Liberty Misfire.

[Kevlar GT]

Bringing this back from the dead I guess but how did you go with the misfire issue? Did you check the coilpacks and/or plugs as well as the other diagnostics you undertook?

[[ITS-STI]]

Also pretty keen to find out some results as i just bought one for the missus with only 97,900kms on it and it is doing the exact same thing... It only does it on idle though? I'm going to do a full major this week so i would like to sort it out then... Cheers, Nick

[smythie]

if it's missing/stumbling at idle (particularly with aircon running) you probably have an O2 sensor on the way out from what I have seen in here

[XXB4XX]

yeah I 2nd that..

I just bought an 04/05 GT with 95,000 on the clock and it idled rough as well.. kept on rev hunting,

I tried the AFM to no avail, then I read these threads about injectors and almost started crying..

Once I changed the o2 Sensor, all is back to normal and car idles like a dream and getting almost 100k's more per tank of fuel!

[BRITTO]

seems fairly common, the wives has done 100xxxkms and same problem, I have changed O2 sensor and still no change. It would be interesting to know if changing injectors fixed the problem for others. It seems to get worse when the car has been driven for awhile. Il keep reading and trying to nut it out. Also anyone know of a workshop manual for these things like the good ol trusty haines or gregories that have got me around every commodore pretty easily?

[SUM12C]

I had a surging problem a while ago and it turned out to be a combination of a broken down banjo filter and exhaust sensor. (subaru thought it was a fuel injector problem and replace injectors 1 & 3 which didn't solve the problem).
There was no error code shown so subaru didn't know what was happening and seemed to take a guess.

[Lick the Knife]

Hi all,

surprised to find this back from the dead. Have spent more money over the last 6 months on getting this fixed, seem to be able to fix it for a while but then it comes back. Have just had after market injectors fitted (half the price of Subaru units), is running OK at the moment (fingers crossed). Have also fitted Xforce catback exhaust system and tried to get it reflashed with no luck, see post in tune forum.

Will post here if the misfire comes back, by the way now have 194,000km on clock. Can't believe how low the km's of some of your cars.

[Adrianb]

I had a similar issue with my 2004 GT.

After doing a whole bunch of stuff myself (Injector clean, pulled the spark plugs etc) I found out that the cause of it was an airleak in the pipping under the intercooler. It was still pushing air through, just loosing a lot of air (power).

New pipe and clamps = full boost, and happy idle!

[[ITS-STI]]

All feedback is appreciated... Still have the problem on the Missus car unless i use air con constantly which reduces the shakes by 80%! Cheers, Nick

[robwayfromoz]

Had the same issue on my 04GT. A new 02 sensor fixed the idle but I stll have jerky acceleration. I'll check the inter cooler pipeing for leaks tonight.

[EUROSTYLE]

Well my turn has come, my 04 gt is shaking like an earthquake at idle and wants to stall even though it's auto but drives, boosts and revs up normal above 2k rpm. My mechanic had a look at it and can't figure the cause but says its running on 3 cylinders!? So tomorrow morning I'm booked in at Subaru.

I hope they can fix it.

[Robbks]

are the cars actually mis-firing or idling very low?

and not once in this thread has anyone mentioned changing spark plugs or checking gaps.
especially given the small tips on Platinum and Iridium plugs that are used. which are easily damaged by mild detonation
personally, cheap copper plugs changed frequently (20,000km) give far less ignition issues in turbo subies than the fancy plugs

given the DBW throttle, keeping the throttle body clean would be essential aswell
dirty TB will restrict the airflow into the engine for the expected throttle opening causing low/ erratic idle.

Replacing injectors??
unless there was a bad known batch, injector failure would be unlikely, possibly a bad batch of seals/ o-rings would be more likely

Subaru's (in older models) have used ignition cut on one cyklinder to control idle speed in the case of the Idle Control Motor (Valve) not working correctly which also apprears as the car running roughly on three cylinders.
quite possible that this happens if the ECU cannot close the Throttel Body far enough to obtain the idle speed it wants.

[LibertyGT MY05]

My manual MY05 had rough idle for most of it first 4 years. Usual service centre cound not / would not fix.
With 1 month warranty left I took it to SVM Lindfield. Was immediately ackowledged as having mis-fire. New injectors were fitted (cost $1200 but free as under warranty). Problem solved 100%. SVM advised that there was a bad bach of injectors.

[EUROSTYLE]

My car was fixed for $202.50...at Subaru Doncaster.

Description: Missfiring, found LH inlet cam stuck 53 degrees advanced. Found filter in banjo bolt LHS collapsed, removed and cleaned up valve, refitted, removed and checked RHS - ok hadn't collapsed, cleaned and refitted, cleared and reset computer due to warning lights coming on, roadtested, rechecked all ok.

[Gambit]

Common issue found on wrx as well, post 06 onwards they fixed the issue, there is actually a service bulletin out on this problem as well,