forester2002s

This doesn't answer your question, but have you tried the following: - Open-up connector R1/B97, and check for 12V (to ground) on B97 when you try to start the engine? - Also, check for resistance/continuity on R1 (to ground)? These tests won't solve your problem, but may take you further down the road...

You may have already done this, but if not I would change the rubber-boots and clean out the CV-joints. Most new boots come with replacement grease. It's fairly easy to completely disassemble a CV-joint, and to clean out all of the existing grease. Once clean, it's easy to inspect the mating surfaces, and to see if there is any surface-wear. The Subaru OEM CV-joints are a thing of beauty, and are well made. Add the fresh grease, reassemble and re-boot. This might help with problematic vibrations. But in any case, it's a labor of love, a kind of Zen thing.

Subaru Brumby (aka Subaru Brat)

A few loose wires, eh? And not firing on all cylinders? And less than a full tank? Yes, I often feel that way these days...

C0116 Code - Stop Light Switch Circuit Malfunction

A brand new fuel filter shouldn't give you misfiring symptoms. But if you want a quick and cheap test, try replacing the old fuel filter (if you still have it), and see what happens to the misfiring.

I my experience, yes when those 'new' fuses blow, it's pretty obvious to the eye. One way to check a blown fuse is to switch it with another of the same rating. Ageing is challenging! Especially eyesight. I find that good lighting helps, but it is a PIT! I always console myself by watching the latest world news ,and realizing that I have little to complain about compared to people in other parts of the world.

Lots of stuff online about 3-wire alternators. Here's one: Alternator System in Your Subaru

What voltage do you read at the battery terminals, with everything off, engine not running? If you have normal battery voltage (~12V), then I would also suspect a failing battery. My logic is that to get to ~12V, the alternator must be charging properly, otherwise where does the ~12V come from?

I've noticed that engines twitch/move/jump when parked with the hood up. A little surge of gas to raise revs causes this engine movement. It may only last a second . This probably also happens when on the move, especially if the gas pedal is pressed down to speed the car up. It doesn't take much to make the heat-shields make momentary contact with the exhaust-pipe. Rattle-Rattle!

+1 on rattling heat-shields. Does the sound still appear when stationary in Parked mode? The best (only?) way to check for loose heat-shields is to get under the car and shake the exhaust system to check for loose parts.

I bought my 2002 Forester new. It was without the cabin air-filter when I picked it up. Subaru must have been penny-pinching back in 2002!

Yes thicker oil will help to reduce oil leakage. And the loss in fuel economy will be minor.

Could the thumping be from the rear driveshaft? U-joints or bearing? If so, I would expect a difference in thumping when accelerating vs. coasting.

Timing Belt: No matter what the ad says, check the T-Belt before use. Never install an unbranded T-Belt, nor one with confusing or deceptive info on the belt. It's just asking for trouble.

Could it be bad gas? But if you've been experiencing this 'misfire' 'for the past month or so', I would expect that you've had to refill the gas-tank a few times - if so, 'bad gas' would probably not be relevant.

Does the horn work? If not, that might also point to the clock-spring.

I am sure that you know this, but WA can mean 2 places: WA = Washington State USA WA = Western Australia

Are you in Vancouver WA? or Vancouver BC? There would be a big difference in shipping rates + customs declaration etc.

Check that the throttle pedal retracts itself fully when at idle. It is possible that something can physically interact with the pedal, stopping the pedal-spring from doing its job OK. Or the spring itself might be 'tired'.

Check the wheels to see if a balancing-weight has flown-off. You can usually see some marks on the rim, where the missing weight was once located.

On my 2002 EJ2.5, I have to let the engine get cold (I leave it overnight), and I have to wipe the dipstick dry before checking the oil level. That's the only way that I can get a decent reading. On my 2017 FB2.5, if I check it in the morning with the engine cold, the dipstick comes out the first time with a good reading, even without wiping it clean (someone at the Subaru design office has finally figured out how to design a dipstick that works!)

Probably just on the driver's side, since your two problems are on that side.

This sounds like a grounding problem. One bad ground on a single bulb-holder can cause odd problems on other bulbs. Is there any corrosion around any of the bulb-holders? Does the metal body of each bulb-holder measure zero-Ohms to a good ground on the car-body?

Check that the PCV valve is OK.