Fairtax4me

I would go get my money back for the cat first. That code is a pariah of the Subaru world. There are dozens of causes for that code and the cats are almost never at fault. They always get replaced, and the code almost always comes right back. I would start by doing a simple tune-up. Spark plugs, new air and fuel filters, PCV valve. Run a bottle of strong fuel system cleaner like Lucas in the next tank.

The pictures I've seen in the FSMs show a small plastic cover on the hydraulic unit and the relay and several fuses are under that, but I don't think I've seen that section in the 99 FSM. Perhaps it is different on 99 and later cars?

Yes, parts ordered from SubaruGenuineParts.com are OEM Subaru parts. SGP is the online parts division of Chaplin Subaru in Bellvue WA.

Coolant not returning to the system from the overflow means the system is filling with air, and can't create the vacuum necessary to pull the coolant back in. Usually this is because of a leak. The only other thing that makes logical sense is an obstruction preventing proper airflow through the radiator. That or one of the shields that is supposed to direct air to the radiator is missing. This would lead to boiling of the coolant going up long grades. Otherwise it does sound like a bad head gasket, which is practically unheard of on the H6, though its certainly possible. These engines almost never mix coolant and oil. Any failure is an external leak or a breach of the fire ring into the combustion chamber.

Same thoughts here. I dont see any mention of that being replaced. Coolant has to be kept under pressure to prevent it from boiling. If the cap is bad it doesn't hold the proper pressure.

Oil burning off of the manifold or pipes should be a light grey color, which often looks white. Black is diesel, kerosene, lamp oil, etc.

Just noticed the picture you added. That brown rusty looking thing down under the engine is the right half of the Y pipe. Basically the exhaust manifold on these cars. Some smoke from that area is normal after changing valve cover gaskets. You really might just want to let the engine warm up and see if the smoke clears before pulling the heads off. If the smoke doesn't go away its because its still leaking and then you would want to look more seriously into head gasket replacement. If it comes to that: The removal process is the same for your car as the writeup you found. You have the advantage of having smaller heads though so the heads are a bit easier to remove. It's a bit tricky getting the bolts out just right but certainly doable. Timing belt and idlers should definitely be replaced. As said before the belt has to be removed to get the heads off anyway.

Is that dryer duct? Dryer duct isn't really made to have air pulled through it. Go get some PVC pipe and remake that intake.

Head gaskets are a normal replacement item on the engine in your car, though replacing them at 85k miles is a bit premature. Usually it's safe to wait until the first timing belt interval at 105k. Someone had the sense to recommend replacing the belt while doing the head gaskets, which is good, but they may not have replaced all of the idler pulleys that guide the belt. There is one idler in particular that fails more often than the others, and it can make a rattle noise when it goes bad. I agree you definitely need a second opinion from an independent Subaru shop.

Hold the presses! White smoke from where? Tail pipe or under the hood? Its common for oil to run down the bottom of the head and drip onto the Y pipe when changing valve cover gaskets. Once the engine is started and the pipes get hot the oil burns off and makes lots of white smoke. You must have been pretty determined if you loosened the head bolts. Those are breaker bar territory with a 14mm 12 point socket. Did you loosen all 6? How far did you loosen them?

Kinda sounds like the Subaru muffler whistle. This is usually most noticeable at higher RPMs under load. Put the pedal on the floor and let the engine wind up all the way to redline before it shifts. The muffler whistle will be very noticeable if that is the cause. This is a fairly unorthodox way to replictate it, but it works if the sound is coming from the muffler. Unplug one of the fuel injectors. Doesn't really matter which, but the easiest to get to is number 1. Start it and drive it up the road and see if that makes it make the sound. It should do it pretty much non-stop. If it doesn't change anything, plug the injector back in and clear the CEL by unhooking the battery - for a few minutes.

Yes, the directions for removal instruct to remove two of the bolts that hold the dash assembly and pull the bottom corner of the dash out 5cm. Then it goes on to warn that pulling the dash out more than 6cm may cause damage to the dash. Of all the things subaru made incredibly easy on these cars, stuff under the dash didnt get out on that list. I think they subbed the dash design out to Honda because they're just as impossible if not more-so.

The shape of the o rings around the spark plug holes changed some in that time period. The rest is the same, so just match it up to the shape of the plug holes on your car.

If you get valve float out of one of these youve got other problems. The valves are so small it's almost impossible within the RPM range these engines run. I wouldn't even consider it a possibility unless you get a tune and raise the rev limiter.

Double check the timing belt. Drivers cam could be a tooth off.

The relay should be under a black plastic cover on the hydraulic unit. Also since it was mentioned, I said earlier in the thread that the ABSCM is under the passenger seat. That is incorrect. It is in the right corner of the dash next to the glove box.

Manual trans doesn't have a neutral safety switch. I hav no idea what a neutral bypass switch is supposed to be, but it doesn't sound right. Too difficult to say what they did but obviously it didnt work. Make them correct the problem regardless. That's why you took it to them in the first place. If the CEL is on because of something the shop "fixed", then obviously they didnt fix it the right way. You've already paid them, don't pay them another dime.

If your car has a MAF sensor the oil from the K&N has worked its way onto the sensor element and "clogged" it. It will need to be cleaned with MAF sensor cleaner and the K&N replaced with a regular paper filter. You may also need to clean the intake piping and filter box to remove any excess oil to prevent a recurrence. If no MAF sensor, change the spark plugs and wires. Even if you don't have a CEL on this sounds like typical misfire under load symptoms due to old spark plugs. Knock sensor is easy to check and can cause this type of issue as well. Search for my Knock sensor 101 thread for specifics on locating, inspecting, and changing the knock sensor.

Subaru used 4 bolts in the bellhousing for every engine they made since like the late 60's. It will be fine. The question of interference with phase 2 heads on a phase1 2.2 block has come up a few times and as far as I know there hasn't been any solid evidence that it is not interference. The pistons in that block have reliefs for the valves, but the reliefs were designed for the valves in the phase1 heads. The phase2 2.2 heads increased valve angle from 15 to... I wanna say 20 or 22 degrees. Which makes it so the head can be shorter (overall height off of the deck) but it also increases the depth (down into the cylinder) of the edge of the valve when its open. I would just assume it to be interference just to be on the safe side. Unless you want to pull the heads and clay the pistons to determine valve height above the piston.

Gonna have to cut them, or soak them in PB and hope they will come loose with some persuasion. (BFH).

Of course it will bolt up. Shouldn't be any issue there. Just have to use the heads and manifolds from your car on the 2.5 short block. Heads have to match the manifold, manifold has to match wiring, wiring has to match car.

Right, U joint placement doesn't matter as long as the rack is centered and the steering wheel is centered. But it's easy to get the u joint 1 notch off when putting it back and not realize it. It's also possible the splines in the "new" u joint are in a slightly different position. It sounds like you haven't driven the car since replacing these parts?

Not exactly. Manifold Absolute Pressure is just a measurement of the difference in pressure between the intake manifold and atmospheric pressure. It's really a useless number to us, but the ECU uses it to help determine air density and calcuculate air/fuel ratio adjustments. Glad to hear its running well. Hopefully it will stay that way.

Yes.

The u joint was not put on quite the same as it was before. I'd remove the joint again and put it back one notch to the left, or should it be to the right? I can't think straight enough to figure how that should go right now. Either way, your rack center is off by 1/2" or so, and adjusting the position of the u joint (and thus the steering wheel) relative to the input shaft of the rack will bring the rack back to center to allow proper adjustment of the tie rods.