ronemus

NGK wires are much better than OEM and cost less. Changing out the wires is one of the first things I do, along with light bulbs and tires.

Do yourself a ffavor and buy one of these: Arcan Jack on Amazon. The long reach makes it MUCH easier to use. Yes, it costs more than a basic jack, but it makes reaching the under-body lift points much easier and the 24" lift makes it easy to get some room to work underneath. Once you try one, you'll be spoiled for life and curse yourself for not having ought it sooner.

fuel pressure of 10 psi is way too low. You may have a crimped fuel line or a plugged screen in the tank.

They're available on Amazon

I prefer Philips Crystal Vision Plus bulbs - they're bright white and last at least ten years (still working when I sold the cars). They're a big improvement over OEM, and huge vs. old OEM bulbs. I put them in my cars within a week of purchase. If your local auto parts store doesn't carry them, they're available on Amazon.

The rear O2 sensor is more likely to be the problem. If the front is bad you would have poor fuel mileage/soot/power loss as well as the P0420. I agree that the aftermarket cats aren't worth it - federal regulations only require them to have half the life of OEM; stick with Subaru. It's good to have the cat on hand - the O2 sensors are difficult to get out and it's easy to tear off the bung; use a backing wrench to improve the odds. IIRC the bungs don't have flats, so you'll need a monkey wrench or very big vise grips.

A pinhole in the hose will leak enough to prevent backflow. A 19 year old hose has likely degraded and needs to be replaced. The barb for the connection to the radiator needs to be clean and smooth so air doesn't leak there.

You could also have a frozen piston or slide - check that they actually move. You can use a c-clamp to compress them - no fancy tools needed. Alternatively, you can make a few hard stops and see if one wheel is cold. If somebody put motor oil or transmission fluid in the brake reservoir, the hoses may be swollen almost closed. Does fluid flow easily when you bleed the brakes? Some models have 2 bleeders on the calipers (pistons on both sides) - you have to bleed both!

The Outback isn't called an SUV, but it is considered a truck by the EPA. I looked tha up when I got my '17 Outback.

A bigger front sway bar will have the most effect on that lifting wheel - more downforce transferred from the outside to the inside. Installing an anti-lift kit (actually it's an anti-anti-lift kit) will also help. Worn stock shocks/struts (marginal at best when new) also contribute. Lower profile tires on larger wheels will take advantage of the other mods, greatly improving the handling. Finally, modifying the suspension so you have 0 toe and -0.5 degrees of camber at all four corners makes the handling neutral instead of the relentless understeer of the stock configuration. I did this on my '90 & '02 Legacy wagons and my '17 Outback, but I can't tell you what parts are needed for your '07. There is no rear camber adjustment in the stock suspension, but Moog makes adjustable control arms intended to bring bent chassis into line as well as extended-range camber bolts for the front. The Moog parts are much less expensive than Whiteline or tuner parts; they do the job well, but don't have the bling.

I've been using this one for 4 years, and it works very well. The low profile isn't needed for my Subarus, the the long reach is very useful for lifting under the diff - you cant get much swing to pump up a low car like the '02 LGT wagon; it's not as much of an issue with the 5th-gen OB. https://www.amazon.com/gp/product/B007G83T16/ref=oh_aui_search_detailpage?ie=UTF8&th=1

The TPMS system can be reset/programmed using an Autel TS501 tool (costs ~$250 on Amazon). I was going to have the tire shop do the programming, but they want $60, as does my local dealer. I rotate my tires at every oil change, so I'll be saving money in just a couple of years. I burns my butt to pay $60 for a 5-minute job.

If you remove the security module, you'll have to install a jumper - the security system disables the starter when it is in alarm mode, and you need the jumper to enable the starter.

You can also buy used OEM remotes in good condition on eBay or Amazon for very little money.

The viscosity of 75W-90 & 75W-140 is actually the same, so there should be no issue. 75W-140 is usually "synthetic" and more expensive, but longer lasting.

The center piece can be transferred from the old flywheel to the new - it's held in by bolts.

There is an solenoid-activated vent valve above the vapor recovery canister uner the right rearcorner of the car; replace the valve and you should be good to go.

The lower slide pin has a captive rubber sleeve, but it's only ~1/4" long.

There is a calibration procedure that you should do periodically - check your owners' manual. It corrects for changes in the magnetization of the body so you can get true readings. Basically you push a button sequence to put it in calibration mode, then drive in a circle in an open area free of nearby steel objects.

Banging on the stud is a good way to damage the wheel bearing. I removed mine with a gear puller after drilling a shallow hole in the end of the stud to locate the puller. To install the new one I just mounted the wheel and used the lug nut to pull it in - no impact, much kinder to the bearing.

It sucks it through the worn bearing. It's a simple sleeve bearing, so clearance develops as it wears. The area around the inside of the bearing is low pressure, so air is sucked in. This isn't just an idea - I've had it happen to me. Mine really let go, and was able to blow out most of the coolant in less than a minute at highway speeds.

This can also be due to a worn water pump bearing;at high RPMs air is drawn in, over-pressurizing the system and blowing out the coolant. A water pump is much less effort and expense than head gaskets, so it's worth checking. A very slow leak of coolant when standing can result in big problems at high RPMs since air is much less viscous than coolant.

I use NGK copper wires that I bought at Sparkplugs.com. They're inductively wound to eliminate radio noise, and use silicone insulation. They're MUCH better than stock Subaru carbon-string wires, and not very expensive. I've had them 8 years and they still look like new.

I tried the Hawk HPS, but didn't really like them. When they wore out, I went to PosiQuiet semi-metallics (http://store.r1concepts.com/store/search.aspx?key=av09874&submit=Search); they have great feel and there was no fade even after 8 back-to-back stops from 60 mph. They do smoke big-time during break-in, but that's their only downside - no noise, low dust, good modulation, high coefficient of friction even when cold.

If your mileage is down that far and you're not getting a CEL, it almost certainly has to be the front O2 sensor. If the sensor was working, you'd get a CEL for the rich mixture.