1 Lucky Texan

try tapping on the MAF - or swap as Ido said above. Even cleaning it might be worth trying. 'dropped' valve giudes can be intermittent.

yeah, outer joints usually not the problem.

I have used; ebay, amazon,subaruonlineparts,fred beans,rockauto,local dealers (even had local dealers match on-line prices) and bought some parts from members of forums.

maybe inspect clutch fork for cracks. Refresh every ground connection as you work. Wire-brush the connection point and both sides of wire lugs and the bolt head ,reconnect and smear with dielectric grease. Use name brand NON-full synthetic GL-5 lube in the transmission. a decent value choice is supertech synthetic BLEND from Walmart. or OEM of course.

check also the big hose from the IACV to the intake. hmmm....I must be confused....but, if the car IS equipped with an Idle Air Control Valve, it won't idle, or will stall at low rpms if the hose (about the diameter of your thumb) , is missing or loose.

clogged heater core? the flow thru it is important for t'stat function. a piece of tubing or 2 and some hose and clamps and you could 'bypass' the heater core for testing purposes I guess.

belt marks are unlikely to line up (maybe every 200+ turns?) but, if you align the crank and cam pulleys to the belt install marks, use a tooth count (look on-line) for your engine to double check timing. if you pull plugs and they are wet, maybe try the 'clear flood' procedure; crank with the pedal on the floor.

in theory, the inner and outer joints get different grease. Not sure it's worth worrying about too much on an older vehicle. I THINK the inner gets about 120 grams of grease. Beck-Arnley repair boot kits come with grease. here's an old thread where I and several others discuss regreasing axle joints; https://www.subaruoutback.org/threads/diy-front-cv-axle-boot-replacement.21119/page-16#post-2063026

does the sound seem to be L or R? it's a hassle, but axles can be swapped to see if a sound follows. There are gadgets like Chassis Ears to help pin-down noises. some folks in the Jeep world like axles from Raxles.com . maybe car-part.com would have some low-miles OE axles. Better if they come from a western/no-road-salt State.

in 'the old days' cars had a start resistor and a run resistor that sorta had this symptom.

he did say fuel was OK, but I was gonna suggest trying some starting fluid in the intake to see if it will run longer.

probably to look on another page of the schematic for the letter K to see where that leads.

dunno about an XT6 but, the shifter on my WRX is held onto the shaft out of the trans with 2 pins....one INSIDE the other!

I bought this set - don't recall which punch I used lol https://www.amazon.com/gp/product/B06XDJXWDP/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

once read of someone fighting an axle that was ~180 out. It had a nail instead of a roll pin jammed in it.

can't remember, just the biggest long drift style punch that fits. If there's clearance to rotate, punch from the other side. I have used a socket extension on a 'started' punch to drive it out from above.

try cleaning the crank pos.sensor. They can get metal debris over time and cause issues.

wow, what a great offer Larry! very nice of you.

I have zero experience with an XT but, the 'stub axle' is probably held in with a roll pin (spring pin really) just move the stub over.

user @GeneralDisorder has a brand of aftermarket ECU he likes (forget the name) but, may be as easy to learn to use that as adapting a physical disty.

in a perfect world, fuel trims would be zero. I've read that single digit +/- corrections are OK. Max I think is +/-35 (not sure if this applies back to 96) and would indicate a big problem. massive vacuum leak or maybe leaking injector or bad diaphragm in the fuel pressure regulator or ????

wow, getting close to 50 years of the green lol.

I always wondered how far back the green inner joint paint was used. 80s? 70s?

next time you feel certain it will fail, squirt some starting fluid or brake cleaner in the intake. If it starts immediately, probably a fueling problem (losing pressure in the rails???) if it doesn't help, maybe a high voltage issue (arcing?)

in this case, I think the 'devil you know' is the best choice. re-do the heads.