GeneralDisorder

That combo doesn't work. 99 single cam has flat top pistons. Compression will be up near 12 and it will detonate like crazy. You need 97 to 99 DOHC pistons. GD

Gee.... 8 ish hours to change trans and diff. Or 6 for just trans. Or not take out the trans just swap the center diff which takes like 1 hour. Also used probably isn't much better. Those center diffs fail on the regular. Dealer stocks more than one at all times. At least - if you are paying for labor it doesn't pencil out. We most often fix them because used is such a gamble. GD

Probably just a lip seal? Measure it up and hit the industrial catalogs. Find your local Parker Hannifin store.... GD

Just fix the trans that's in it. They are simple units. Probably needs a center diff. GD

Removing the engine load doesn't prove anything. It just means the IACV was at a point where it could supply enough air for a decent idle when not loaded, but couldn't compensate when loaded. If you have codes for the IACV then try a used one or get a new one from the dealer while you still can. The other possibility for idle control codes is a bad inhibitor switch on the automatic models. GD

Excellent. Though JB-Weld putty would probably work best. Don't forget to coat it in copper spray. Coat the world in copper sprayz!!! GD

Time is money. I can't make a gasket out of anything for $12. That's a little over 7 minutes of my time. You'll learn this as you get older. Your time may be worthless now, but at some point you will want to get something done without it taking forever. The dealer gaskets are excellent and fairly priced. There just isn't a reason to deviate from them at this time. GD

In our experience this trim issue under load is a problem with the MAF. Have seen this and corrected it with a new Denso MAF on multiple occasions. GD

I imagine there's a certain amount of cultural impermanence when you live on an island that periodically gets proper wrecked by tsunami, hurricane, earthquake, nuclear meltdowns, and Godzilla..... though I'm not sure how much better a newer Subaru would fare compared to an 80's model against atomic death breath. Perhaps they sell NBC retrofit kits for JDM..... GD

Yeah we always used .815 and that solved any issues they had. I'm sure .810 would be fine also. GD

Right - there are other "exotic" causes but only go there after doing the VE calculations and watching O2 sensor data and you are SURE it's not one of these. I have not seen that generation of top feed injector have any issues, and the fuel filter is in the tank so it's unlikely to be an injector issue in my experience. Subaru's don't typically have low pressure either - the pumps usually just die completely if they are going to have an issue. Again failure rate on that model year of injectors and pumps is basically zero. I have not heard or seen of such a thing. GD

Long Term fuel trim is WAY high. It's adding fuel like crazy. This means the computer thinks the mixture is lean - either due to an air leak past the MAF, bad MAF, or bad data from the primary O2 sensor. With those newer models we do see a fairly high rate of MAF sensor issues. And they aren't throwing MAF codes either - just running horribly and trimming fuel under load. You need to do some Volumetric Efficiency calculations with your datalog information to give you a sanity check on the MAF readings. Top suspects would be the MAF and upstream (primary) mixture control O2 sensor. GD

Very likely to be a HG problem on that engine. That and cracked heads are pretty much the reason you almost never see those (running) anymore. Too expensive to repair and no parts available to do it right. GD

Whatever happened to the Skipper? GD

That's correct - their customer service is all US based. We use their products exclusively where we can. GD

The man wants to spend 10k DOLLARS not 10k HOURS working on an engine swapped 80's pile that's worth $75 in scrap metal. He didn't post this in old gen. Sheesh. GD

Heli-coil. If you have ASV spacers just install a standard 15mm long heli-coil and leave the tang on it. Go to the dealer and get exhaust studs for 2000 Legacy. Let them stop on the tang. If you have no ASV spacers then heli-coil the cylinder head as you would any other thread repair. www.threadtoolsupply.com GD

Broken drivers side timing belt. Watch the distributor rotor while cranking. Bet it doesn't spin. GD

Melted ASV "silencer" (muffler) got sucked into the carb and glued it shut when it cooled down and solidified. Will likely require a carb tear down. GD

Fel-Pro on the intake gaskets is a guaranteed fail within 5k miles. They are complete trash. Why would you take the risk for $12? GD

Tons of known issues. Turbo failures, piston ring land failures, oil pickup tube failures. Google those to get started down the rabbit hole. 2005/6 Legacy turbo models with over 200k are synonymous with boondoggle. As far as I'm concerned that's a rolling chassis that needs a new engine. Whoever buys it just doesn't know that yet. GD

The 2.5 block IS a stroker kit. You have no idea what you are getting into here. Back up and find out what you HAVE first. All 2.5's are not the same. GD

This.... It's hilarious. Lead?! Really? Seriously tho stop giving advice. You're going to hurt someone that's not your "kin". GD

Pictures of the piston tops will do. Don't need the VIN. GD

What years?