montana tom

It's a basic idiot light switch. I keep them in stock, and I routinely replace them when a car comes in for other work. Subi's are extremely forgiving about running low on oil, but when that light starts flickering or worse yet, stays lit, you need to check things out.

Near the front, on top, on the pass side. Between the alternator and the power steering pump. Is this motor oil or perhaps it is power steering fluid?

oil pressure sending unit

Confirm that your JDM has (VVT) variable valve timing heads; if not, use only the short block and install your heads with MLS #642 Subaru turbo head gaskets. Remove all the JDM external parts. Strip it down to a long block and install your original intake & other parts. Confirm your crankshaft sprocket is the same as your original; if not, use the original. Be sure not to damage any ears while removing from the crankshaft. Only install the original equipment timing belt and all new components. Use only an original equipment (OE) thermostat, not an aftermarket one. NGK plus and wires

Outbacks have separate high and low beams. Legacy has a combined high and low beam.

This job looks horrendous, but it is not that bad. I have done three of them; here are many pictures, but not much write up on the process. https://permies.com/t/197844/Black-Car Like most jobs, getting started can be the hardest part.

You are not giving us any information. I assume your having trouble filling the tank? If so, your Evap system has issues and must be evaluated. What codes is it throwing?

The heads must be 251's, be sure to use MLS factory turbo head gaskets. The PCV arrangement may need to be modified. Pistons should be ok although new rings and cleaning the drain back holes in the pistons is always a good idea.

I suspect the driveline as well. Best to disconnect it at the rear end and see how smooth the joints feel. CV 's can give a vibration on acceleration. Tire ballance is always worth checking. Enjoy your new outback, I consider the second generation to be the best ones made.

Rear driveline, usually at the u-joint directly behind the transmission. CV axels can do this as well.

Yes it will

Don't buy a cheap one or you'll be relacing it again soon. O.E. or denso

Yes it is.

I suspect the flywheel.

2004 cars issued to California had round port heads and drive by wire throttle. 2004 cars sold to the rest of the country are the same as 2003.