1 Lucky Texan

how many miles on the 05's struts? I'd put new on for the trouble.

as a triple check, search online for the tooth count for your engine. Good to use especially after you turn the crank over with the wrench before firing it up.

just make darn sure it isnt' the pressure sender - it's kinda behind the alternator I think.

any oil in #3's plug tube?

uh-oh, 'could' be the waterpump. It has a weep hole. Have only read of coolant coming out but, IIRC, it could also leak oil if the the other side of the pump has a bad seal. your engine may be different from mine - plus, seems like your leak could be under pressure and I think the WP's oil side is just splash. anyway, this older thread on another Forum might have some pointers; https://www.subaruoutback.org/threads/3-0-oil-leak-help.312057/

is there a 'motor control relay' or similar? Had an old Nissan for my daughter that would intermittently stall - it was a relay dropping-out.

what year/model? if someone were spraying carb cleaner, starting fluid or maybe a stream of propane gas into the intake, would the car try to keep running? any CEL or pending codes?

search for videos - soob axle replacement and re-booting.

some of that seems like a vacuum leak but, GD likely has more to go on now so, maybe he will reply. the fact that it was better after the reset does somewhat point to a sensor though......?

glad you're OK.

also, would be no surprise a '99 needs a new knock sensor. and ground connections refreshed.

is there any smell of gas at the tailpipe when cranking? if not, you have a fuel problem since it didn't fire. if you do, perhaps the cylinders are flooded. pull plugs to see if they are wet/crank with the pedal held to the floor to signal ECU to stop fueling. It's the 'clear flood' procedure. I suppose it's possible to have multiple issues, so, maybe check for spark.

cycle the fob on/off a coupla times - maybe a security feature is in play?

IACV hose drop loose?

This is a good thread with some great pics illustrating some of the crazy valves and piping involved in the fuel tank's operation; https://www.subaruoutback.org/threads/whats-inside-fuel-tank-edition-leaking-fuel-tank-autopsy.510193/

any different numbers stamped on the parts maybe?

maybe IACV hose is cracked or partly loose? is that timing supposed to be -10 ?

if you have a part number, check ebay UK?

what codes come back (or show as 'pending') after the work that was done? is the car new to you? if not, has it gradually gotten worse or was there a wreck or some work done just prior to the problem?

details on car? and what are the symptoms of a/c problem. (seems like the blower fan?)

all I have to offer is, sometimes a bad throttle pos sensor will create trans problems.

GD - no chance of 'reverse soaking' or somehow flushing the top valves of the tank? Seems like they just gunk/varnish up and some fuel-safe solvent, and maybe a little persuasion with an air hose or ??? might pop them loose. Anyway, my MIL's Forester had that happen (she used here car very intermittently) and it took a LOT or persuasion to get Subaru to replace the tank.

I'd consider pulling hoses off the canister while filling, to somewhat prove it was bad. there may be 2-3 hoses on it so, you really need a diagram.

I have read the the FSM has a weight limit for canisters? - if they are too heavy with fuel, they get replaced. Not cheap. The system in newer cars is supposed to limit the chance for fuel to get in there but....????

battery cables might be an issue, they can be quite corroded under the insulation and limit current to the starter. Feel of them and see if they get hot? Or wiggle them while someone is trying to start the car. Also, whack the starter with a piece of wood - sometimes that will 'encourage' better contact between the plunger's disk and worn contacts. If the starter never responds to that, the issue may be elsewhere.