gessvt

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'05 gaskets are orange silicone/rubber as well.

.... some also speculate that it's last on the chain in the fuel rail which causes slight lean conditions thus eventual low compression. but the rails and lines are equidistant...

 

Could a Stage 1 tune correct this scenario? i.e. is the stock tune possibly too conservative, causing a lean condition?

Yep. A couple more days of driving and no issues.

144 and 145 psi in cylinders 2 and 4, so hopefully that rules out bad ringland or gasket. Tech swapped out plugs from cylinder 4 and 2, and I'm driving for the day. Tech said he's seeing evidence of a leak in the #4 injector, and that he has not been able to get any code besides P0304.

 

Car didn't throw a code on my morning drive. It pulled fine, but RPMs drop to around 200 when out of gear for a few seconds, then recover to 1000 RPM.

 

I think we're getting closer to identifying the injector as the culprit.

 

Tech replaced injector #4 and the air fuel ratio sensor. I got the car back last evening and it is idling smooth.

 

During the diagnosis, the tech swapped coils and plugs before he investigated the injector. He stated that the car would not go into a closed loop, and that the misfire code would not set in an open loop. This is why he recommended replacing the air/fuel ratio sensor.

After replacing my injector on cylinder 4, car ran really smooth for a few days, then started to get worse and after a few days was running rough again. Code also came back (Misfire on 4).

 

My car runs rough at idle and lower RPMs, not to the point of stalling ,just rough. I also get 30% worse fuel economy than I should.

 

I want to determine what to check next. I have read MAF sensor and also the coil pack. Does the fact the car ran fine for several days while the computer adjusted eliminate the coil packs, or point to something else?

 

I don't want the stealership blindly replacing things and charging each time.

 

Its a 2005 Subaru Legacy GT with 136,000 km.

 

Did you get a compression check? Let me know how this turns out. I'm about to have the #4 injector replaced for the P0304 as well.

cylinder 4 only misfire- get a compression check.

 

144 and 145 psi in cylinders 2 and 4, so hopefully that rules out bad ringland or gasket. Tech swapped out plugs from cylinder 4 and 2, and I'm driving for the day. Tech said he's seeing evidence of a leak in the #4 injector, and that he has not been able to get any code besides P0304.

 

Car didn't throw a code on my morning drive. It pulled fine, but RPMs drop to around 200 when out of gear for a few seconds, then recover to 1000 RPM.

 

I think we're getting closer to identifying the injector as the culprit.

33 degrees this morning, and it's idling worse then when it threw the P0304 code. I'm really surprised that I can't get a misfire CEL at this point.

 

Finally got a CEL. P0304 again. Local shop replaced coil on #4. Car ran fine briefly, but now will not idle. The shop wants to replace the O2 sensor, but I'm thinking that they didn't hook up a vacuum line somewhere? They are not charging me for the coil, but I'm nervous that this is going to snowball.

If you don't mind my asking, how much was it to have the injectors cleaned?

33 degrees this morning, and it's idling worse then when it threw the P0304 code. I'm really surprised that I can't get a misfire CEL at this point.

check the o2 sensor too. i was misfiring on 3 cylinders, new o2 and im gtg

 

Were you getting a CEL with the bad o2 or just rough idle? I haven't had a CEL since the original P0304, but it's idling the same.

Subscribed. 75,000 mile 5MT. Car originally threw P0304 after idling roughly for a few weeks. Before P0304 I replaced plugs with OEM NGKs. Compression test done at the same time (all good). After P0304 I replaced intake manifold O rings and BPV gasket. This all in the past 2 months.

 

Car continues to idle very rough but no CEL. Pulls strong and no issues at speed.

 

Time to replace #4 injector?

Tried to replace the gaskets (2005 LGT) in my driveway this weekend. Best of luck getting the wiring harness bracket removed from the manifold. Even with the intercooler out of the way, there's barely any room to get an open ended wrench in there. In addition, the hoses that are routed underneath the bracket on the passenger side are packed in so tight I had no idea where to start with them. This isn't an easy DIY by any stretch of the imagination.