1 Lucky Texan

see how 3 lines go to the carbon canister? remove one at a time before refueling, then see which one lets the car be 'normal'. that system has multiple modes of failure. My MIL's 2010 Forester had to have the tank dropped for stuck vent valve. as mentioned by wtdash , connecting the green test wire will cycle all those valves, at least put a finger or hose up to you ear on each one to make sure they cycle, if they do, then likely a clog or bad valve is the problem.

separately - youi wouldn't know which action improved things if the engine runs better.

even though it could likely throw a coupla evap codes, try pulling various hoses off the carbon can. , refuel and drive. You may at least discover which system ,or, where in the system the problem is. If the canister has ever been flooded with fuel from top-offs, I'vread that carbon particles can travel to a valve and cause issues.

wel, if exhaust is severely blocked, a vacuum gauge will show you, check youtube and other on-line info on that. many folks have had bad/cracked knock sensors on older soobs that force the ECU to pull timing - kills power. if you own a smartphone, tou can use Torque Free app and an ELM327 BT or similar adapter and get data from the ECU. That might tell us about ignition timing and a:f ratio corrections. one idea, if you do a battery reset, pull neg term., press on the brake pedal, wait 10 minutes....w'ever , does the car run the same or better? if better, I'd suspect a sensor-related issue, if the same, might be more physical/mechanical. restting the ecu forces the use use of the 'factory rom map' and the car 'forgets and must re-learn adjustments from a:f and other sensors.

strut bearing mounts? or the upper spring 'seat'? there's usually an arrow or hole that points outwards (towards the fender) also, the washer at the top must have the bevel/cone side against the bearing.

any indication the trans pan is dented?

60 secs of heat is quite a bit. I 'accidentally' discovered what has been explained on the Forums once or twice by the 'gurus' - after warming the nut with the torch, THEN (carefully) spray with PB Blaster or 50/50 ATF-acetone mix. As it cools, it will draw the penetrant in. It was strut work that finally convinced me to buy an impact wrench. Wish I'd had it 35 years ago. I know it sounds crazy but, try some force in the TIGHTEN direction, maybe a little back-forth on it will bust the rust!

sure those were working before? check the bulbs with an ohmmeter.

I guess it comes down to services available on Kauai or within reasonable shipping distance? you might call the NAPA place on Oahu and see if there's anything they can do for you or some shop they could recommend?

IF there were an old-school driveshaft shop, or, an automotive machine shop on Oahu or elsewhere, maybe you could get yours to them? some drive shaft shops can un-stake joints and re-work the shaft.

usually, trans get under-filled when folks don't idle the car to check, so, I thought maybe it got diff fluid put in or w'ever by a SpiffyLube that wasn't familiar with soobs. maybe try some Trans-X to free-up gummy valves?

fluid LOOK OK? maybe someone put diff oil in there? any codes stored? scan ecu for codes. bad knock sensor will kill performance and sometimes not set a code. check timing, may have slipped a notch. (when eas the timing system serviced last?)

I think the suggestion was related to finding a soob-centric independent mechanic. based on other postings, pretty sure ThosL has exhausted that search, but, if someone knows of a shop near him please post it up!

not cool enough this morning to 'test' the lithium grease trick in the starter. I've seen diagrams of the internals and I'm not convinced the spray gets far enough forward.

I got an after market 'universal' one for my WRX. It came from a parallel universe since I had expand the spring wire and use pliers to put a 'recurve' on the ends to prevent them digging into the cap's plastic. It does hold the cap but it's still not a great solution.

so many things can cause a Po420, it often isn't the cat (though cats can of course be bad, just don't replace it without sure knowledge that is the bad part) in addition to confirming a secure connection as mentioned above, general ground connections should checked and refreshed. the CPS is located at the center of the front of the engine above the crank pulley. One bolt holds it in. They can fail when warm on older cars, I read once of a flaky one working after cleaning debris off of it. Replacements are not terribly expensive.

czny - you might investigate axles from HERI, they have more extension.

if you can't feel a problem, seems unlikely any damage is being done but ?????

late doing oil changes on both my cars but today I got the WRX on ramps. changed oil/filter, new wiper blades all round, tightened the clamps ts the fuel line 'buffers' or w'ever they are - last year I smelled fuel in cold weather, looked around/inspected stuff. one weird thing I tried...when I changed strut mounts and struts, I noticed a drain hole (???) on the underside of the starter. It has been making dragging noises for a long time now when temps are under 50* or so. I managed to spray some lithium grease up in there with a tube on the spray can. Dunno yet if it will get even remotely close to the pinion gear's shaft - figured it couldn't really hurt anything. fingers crossed. need to change oil on the OBW

there's a protective fuse built on the back of the power port itself. fuses can look good but, best to actually test them with an ohmmeter.

there's an argument for keeping intake air cool and dense for xtra power. Questionable whether the difference could be felt in a daily driver. I read once of a crack in a throttle body and coolant leaked out there. Extremely rare but maybe he was bypassing the TB due to a leak?

gd - like these? https://www.amazon.com/MonkeyJack-Pairs-Couplers-Connectors-Adapter/dp/B07486YR68/ref=sr_1_3?ie=UTF8&qid=1510233251&sr=8-3&keywords=r12+to+r134+valve+adapters

well, there may be 2 reasons to send coolant thru there; to prevent icing or it's an emissions thing.

not sure where to put this post. And I can make no guarantees about safety/quality of using these links. just fyi https://sl-i.net/FORUM/showthread.php?18087-Subaru-Factory-Service-Manuals-(FSM)-Every-Model-USDM-EU

from what I've read, the fear is moving the MC seals over some debris or corrosion located where there is usually no travel - and tearing the seals. probably more of a concern on old and/or neglected vehicles.