Misfires

I guess I'm going to try wires, and pcv...then fuel stuff. If I find oil on soak plugs after replacing the o rings and valve cover gasket should I try to return them?

The O rings? I would keep them if they're better than your old one or if the old ones are damaged

oil in plug wells? You have a valve cover gasket leak or the spark plug o ring is leaking. It's NOT wires and probably not pcv.

Check for vacuum leaks. Also check the fuel injector electrical connectors. I had a P0300 misfire because of a unplugged connector.

Couldn't see difference between old and new so went ahead and replaced them
That's what I fixed. ran perfect for ~100 miles then boom back to square one with worse misfiring

Does it have blow by? Could be piston rings on that cylinder

Take it to a professional.

What kind of car is it

ringlands

starting to sound like it
>look in manual
>"piston replacement p. 2-14"
>go to page 2-14
i thought i was getting good at this car stuff. clearly a misjudgement. i am remedial and this all looks like sanskrit moonrune cartune fuckarooning that i can't comprehend. sounds like a swap is going to be cheaper/more on my inferior brain wavelength. also could put in the h6/ez30d if i find a standalone ecu thats cheap
i'm guessing ringlands, blowby, low compression in one cyl are all closely related/same thing- replacing cyl rings and etc? which i have no business doing apparently.

going to look at this now, fingers crossed there's some stupid cable not plugged in.

leak in exhaust system before o2 sensors possibly, try disconnecting both front o2 sensors and driving the car, if it doesnt get better then its probably an ignition problem. Check your compression on that cyl, if its good then start narrowing down through the ignition system for that cylinder. Could possibly be a valve that has too little valve clearance as well.

ok. are these the o2 sensors i put in the catalytic converter?

also, went back and checked the valve gasket bolts. there's one bolt that doesn't seem to lock (i can just keep tightening it forever). i retightened all the other bolts, the accleration improved (shorter misfire episodes on take off) but soon returned to the shitty way it was in about ~4 miles of driving. kind of same pattern after i changed the gaskets. could it be misfiring because of the loose bolt, and slowly rotating it out somehow? just a thought.

if that means an air intake, probably

try this trick to get the code if you don't have an OBD2 reader nearby
scoobypedia.co.uk/index.php/Knowledge/ReadingECUCodes#ManuallyReadingECUCodes

And the code meaning table
scoobypedia.co.uk/index.php/Knowledge/SubaruTroubleCodeDefinitions

I'm the one who originally came up with the blow-by theory.
Now I'm thinking it's just something as simple as the motor not maintaining a seal. I'll guarantee if you have this bolt and thread repaired, it'll run right. Hopefully the thread in the block isn't to buggered.

I'm guessing O2 sensors are stuffed, providing a false value to ECU. When engine is cold the O2 sensors do nothing, the engine runs in open loop, until the sensors heat up. When they get hot enough they activate, and if they are stuffed, they will throw all sorts of codes about lots of other parts. The O2 sensors have a catalyst that is slowly used up over time.

How many miles on the clock. 160k miles and most O2 sensors start to stuff up.

If you can get fuel trims it would be a good way of knowing whether it's an air leak or not. I've had the same issue on my car, rough idle and sporadic misfires, would stall at red lights, turned out to be air leaks on the intake around the MAF as well as a hole in the intake manifold.

shit was fucked yo