brus brother

Might try swapping passenger side over to driver side to see if the issue is the box or just aftermarket crap axle? A lot of work but would be diagnostic.

The older I get, the more clearly I recall things that never happened.

From the School of Look No Further, I would shimmy under and inspect the most recent axle foray.

or "bad gas"?

lifetime warranty or lifetime of replacing with aftermarket axles from what is reported hereabouts. swap the front tires R to L and see if the rumble follows the tire. probably best replacing tires as you plan and then start looking for demonic possession if symptoms persist. In the meantime, turn up the radio. common things happen most commonly.

check and reseat wires into coil and on plugs (also verify proper order usually marked on coil) spray water at night on wires to see if any arcing visible (sparkles) I used to have an issue when damp/rainy outside 05 OB (#3 cylinder) and thought I needed to replace coil but just reseated wires and all has been good since.

Had a 2000 Legacy and after a while it developed a whine from the pinion gear. Been a while but I think SOA replaced tranny under warranty. In law's same vintage HG went.

Stomping on gas and taking off from a parking spot sounds like drive shaft, U joint. Any play? Subies are robust but not meant for Dukes of Hazzard jumps.

After you erase the codes, start the car without depressing the gas pedal. it will run rough as the computer relearns the car. The first thing is to start the car and let it ideal for a few minutes. Nothing turned on and don't touch gas pedal. Let computer relearn the car. Best done with 1/2 tank of gas. The sequence described in the video is what I remember but It might take a few tries. I would try and plan on getting systems ready en route to test center. As soon as you get monitors ready, get in line at emissions testing center! Good luck.

excellent point. I have a writeup here somewhere with pictures of that 'gaiter' with broken wires. Video of someone with similar issue who decided to disassemble the rear gate innards. I was lazy and just noted the broken wires, used a piece of dental floss (I'm a retired dentist) to pull the broken piece through the gaiter, tied on a piece of wire as a splice and dragged it back through and made the connections. I think there was a total of three wires that were gerschmucked and in need of handiwork. Lasted until I canned the car.

Drove my 05 OB with P0420 for over 100K miles after it first popped on. Car died a peaceful death around 225K. It's an emissions code. Might come and go. Cruise will be disabled when the CEL is on. Get a cheap code reader if you think you might have other codes of concern. If you need inspection, there is a sequence of clearing the codes and getting enough systems ready to pass. I was told the tolerances on emissions was so tight on that car that it was easily over the limit. I replaced O2 sensors and original cat (bank1) with aftermarket and code immediately came back. Piece of black tape over the blinky dash lights and drove on. Cardoc over on subaruoutback.org has a couple hundred pages of posts that try to solve issue but I never got to the point of success. Stopped throwing my wallet at the car.

That "cheat fix" may fail in time. Try this next time:

cost to ship versus cost to replace SAFETY FIRST, SECOND AND THIRD

GD's $9000 potential hit sounds like it's time for Craigslist For Sale By Owner for possessions unless family heirlooms. No white knuckle driving and a moment to reassess what one needs to carry into the next phase of life. (Says the geezer with a garage and basement filled with junk.)

Keep us posted.

sell the bed? buy new? sell everything, stuff the outback and travel light. go Maryland Terrapins! My daughter and hubby paid to move from NYC to here in CT beginning of Covid. Since sold off most every bulky item including their bikes, tables, chairs. Currently AirBB monthly around the world. From London to Aruba to France. Worked for them. Hope your daughter's move is safe and worry free for dad. I guess you costed out driving renting a one way uhaul cargo van? Not as much fun if both passengers are able drivers and playing follow the leader...

Hey Paul. Was this you and your aging eyes? blind corner.mp4

I have a 2008 OB with chronic, migratory and recurring heat shield issues. 135K miles in the rust belt. Years ago when it first started, car was in for a free oil change at SOA. I always enjoy the up-sell conversation when in for the "free" service... "Sir, you are due for your headlight rotation. I see you have your kids in the car. You probably want to take care of this now." I always decline, telling them they are not my kids, so not my problem. Besides, I do most simple work myself and rotate the headlights as per manufacturers schedule of maintenance. OK Back to the heat shield noise. The tech proceeded to bang around with his hand on the exhaust and once the noise was located (to my horror) he inserted a self tapping screw into the exhaust. But what he actually did was drill ONLY through the heat shield but NOT actually into the exhaust pipe, wedging the shield in place, eliminating the heat shield from rattling. Phew. In the past I used stainless steel hose clamps (per USMB recommendations) where straight runs allowed but recently ran into a new loose heat shield on a bend that defied my attempts with a clamp. Pulled out my nut driver and a self tapping screw and voila, NNM (noise no more.) Sounds like OP may have figured out his noise but just wanted to tell an old timer's tale of yore. Now, get off my lawn. ;-)

P0420 for 8 years gas mileage never altered (even with the black tape). Car ran great all those years. There was another trick of installing a resistor on one of the O2 sensor wires and while the P0420 disappeared, another code popped up instead. If you end up not getting a resolution, you can erase the code with a $20 reader and cruise will work until the code reappears. You can also just read codes on a routine basis and allay concerns if you fear a code warning that the rear tires are about to fall off. I think that code is Pwtf! Seriously, I wish you luck. Hope you can report good news.

check wheel for balance

yeah, use the spare as a placeholder as you swap tires L to R or forward aft.

My experience with drive shaft was when taking off from start and I would feel it in the center as ido suggests.

Roadside assistance only available in New England ;-)

new tires? if lug nuts tight try swapping tires back to front. see if noise travels with tire. possibly defective tire. common things occur commonly.

lug nuts tight?