nvu

Did your car year come with an oil cooler? Was it replaced during the rebuild? Kinda straying off your main question about the heads but the engine's seen bearing failure, so replacing the oil cooler is a must on the next rebuild if your car has one.

At this point I'm guessing and throwing out ideas since changing the maf made some improvement. Check the connector and wiring itself to the maf. It might not apply here, on my turbo ej25 the fuel trims would drift too rich or lean over the years, I've always attributed that to dirty or failing maf and replaced a couple, it fixed the problem. Randomly on one of the refresh builds, I broke the tab on the connector and it wouldn't lock. Ordered a connector and found that one of the wires felt very stiff, it was the heater power for the maf. I chased it maybe 1ft into the loom until it got flexible like the rest of the wires. Then ordered a premade made pigtail and spliced it in. Haven't needed to replace any maf's since. Then again the loom ran near the turbo area of the bay.

You did mention you had a 96 ecu? Chasing the readiness monitor is near impossible with those as the programming was flawed. If you turn off the engine, it loses the readiness state. Even smog in CA has an exemption for 96 year subarus.

No, smooth limp mode mainly points to electrical. Well you ruled out most mechanical issues. So fuel pump, injectors, spark, are in good shape. It doesn't rule out vacuum leaks though, in limp mode the car runs super rich and masks any leaks. It's mainly sensor and electrical issues now. It's not exactly the maf though. Unplugging the maf forces the ecu into limp mode, it ignores most sensors at this point. If you really want to make sure, you'd need to throw your maf into another car or borrow one from a working car.

You'd have to turn off the ecu first. With car completely off, unplug the maf, then start it. The car will be stuck in limp mode until you reset the ecu by unplugging the battery though. Then again, maybe the ej22 is different. This method works on later ej20/ej25 ecus. 2002-2005ish at least

Could your ecu still run in limp mode with the maf unplugged? Just as a sanity check, drive the car and warm it up until it does the stumbling in idle. Turn off the engine, unplug the maf, start it up again. It should be in limp mode and running rich, but should be idling smooth. If it's still rough, that could point to basic things like injectors, vacuum leaks, spark.

Not exactly that bolt, but similar issue. I've had bolts seize to the bushing collar. Depending on how accessible they are, my main go to is hammering at them with a beefy socket extension. I have a used impact extension just for punching things loose. The black ones that don't shatter, chrome ones do. They're also easy to grind to whatever shape needed. If you already have the replacement lateral link, you could cut out the old link with an angle grinder.

Is it P12003 and M700154?

https://parts.subaru.com/a/Subaru_2014_Forester-25L-CVT-Base-Premium/_54106_6029067/REAR-SUSPENSION/S13-201-01.html Not sure if this is your exact model, click around and see if you can find it. Or start from https://parts.subaru.com/

Mark it with a paint pen. Or use a center punch. Then count the number of turns when taking it out. Do one side at a time. If it's really aluminium, it sounds like the bearings are so worn they're grinding away the case.

Are you talking about the stub axles? It's a tossup, some are spring clipped and you can just yank them off. Some are circlipped, no other way than opening the trans. The old one's broken anyways, cant hurt trying to yank them out. Put the cups and roll pin back on, pry at them and see if they pop out.

They look like wave spring washers maybe? https://duckduckgo.com/?q=wave+spring+washers&iax=images&ia=images

Second this. If the previous two were composite gaskets and you're going to MLS, definitely have the heads resurfaced.

I'm no expert, but I haven't used copper spray on gaskets and had good results over the years.

The dogbone thing? They've all been the same length as far as I know, at least for EJ series.

Turbo needs a turbo capable ecu. All the turbo ecu's in your era need dohc. It's going to cost more both in money and time trying to turbo an sohc setup than dropping in a dohc longblock/ecu.

For the engine, doesn't matter much. Possibly help other mechanics not expecting a burning hot object so high up on the engine. That's where the trans dipstick is.

is the car in your posession? sounds like gaskets weren't done right from your story. you just need to confirm. no need to flush, start the car with engine cold. leave the radiator cap open and top off with plain water. idle it for 15-20mins, topping off with water until it's warm and the fans kick on. if you're seeing bubbles everytime you rev it, thats pretty much headgaskets. if not, it might be cracked radiator or leaking hose joints, because you mentioned steam. either way, if there's no bubbles, put the cap on and drive around, soon as the needle inches up, pull over and check if the reservoir is bubbling. any bubbles by now is headgaskets.

probably a good idea to install an oil gauge at this point. it's a non turbo so you probably have plenty of room to tap into the rear oil gallery plug. search for oil pressure sender gauges. i prefer the metal can looking ones with no plastic connectors that melt when placed near a turbo. don't ask how i know. it doesnt have to be routed inside. the gauge could live in the engine bay for diagnostic, taped to the hood, or unplugged if not needed.

Is the mount still not in the hole? Had something similar happen before. The bolts didnt line up with the crossmember holes. I think I removed the dogbone and put a ratchet strap on there to pull the entire engine back towards the firewall. Then slowly lower it while prying things into place scrap wood sticks. Like lower it so it barely presses the metal, then pry it until it slots in the hole. No ideas on the whining noises.

On a forester, everything is lifted an inch vs impreza chassis. If you had a forester body and put the impreza shaft in, you can put washers to lower the mount point. Not sure if anyone's done the reverse.

Haven't confirmed myself, but I believe Foresters have thicker carrier mount vs imprezas.

One area under the turbo that could leak, the drain port, gasket and tube. If you can get a good view of that, it would rule out the turbo. Here's where it is on a car with no lower heatshield.

Wastegate looks fine, clean it up and no lube if you feel like. BTW, your oil feed line looks bone dry. Don't touch it if you don't need to. At this point it's probably work hardened and probably will crack if you fiddle with it. Probably use an old cellphone and record video, tape it on a stick. Look under the turbo see if it's wet. Hopefully it's not the turbo and something else on the car.

Just pick some more up from the hardware store or online, They're M6 10mm hex head bolts, flanged is better or you can use washers with nonflanged ones. You probably don't want lock washers, these bolts heatcycle the most and like to corrode and fuse in place. It's better to have them loosen than get stuck and rounded off in the car. They just hold the heatshield in place any length is fine, probably 10-20mm is good enough.