ammcinnis

It may or may not "do any good," but a pulse-type charger should ONLY be used with the battery disconnected from the car's electrical system. The narrow, high-voltage pulses intended to de-sulfate the battery can damage the many electronic modules used throughout modern vehicles ... including our Subarus. Subaru of America has even posted memos to this effect in their dealer tech publications.

See the attached excerpt from the 2015 Legacy/Outback FSM. It is important to match the transmission code, perhaps even more than matching the VIN. It would also be worthwhile to verify the code on your current transmission vs. the transmission code specified on the vehicle's model number label. That's because the front differential was integrated into the CVT housing, and 2.5 Legacy and 2.5 Outback had different final drive ratios. You don't want to get this wrong! Per the http://parts.subaru.com web site: 31000AJ570 => 2015-2017 Legacy (3.900 FDR) 31000AJ610 => 2015-2017 Outback (4.111 FDR) 1.05-ID-Identification.pdf

Maybe; maybe not. Some Legacy/Outback owners have reported the same results as you, but others have reported that they needed a small shim to fully secure their Group 34 battery. I wouldn't "worry" about it, but using a manufacturer-supplied battery spacer removes any doubt. What you do not want is for your battery to be loose enough to rattle around in its mount. Your car, your choice.

Once again, reason rears its ugly head!

If I remember correctly, by MY 2017 the higher-capacity battery was being installed at the factory in both 3.6 and 2.5 models of Legacy and Outback.

Who woulda' thought?

A battery's BCI Group number specifies its external physical dimensions and terminal configuration ... nothing more. The battery manufacturer is free to select the battery's internals as they choose, perhaps to optimize for one parameter over others. There's a reason that there is such a range of prices from one battery to another, even within the same Group number. This isn't anything new; it's always been this way. One manufacturer may choose to optimize for high CA/CCA, another for RC/VA capacity, another for reliability and longevity, another for shock/vibration tolerance, another for low manufacturing cost, etc.

(Hits head.)

There is an important distinction that hasn't been mentioned yet in this thread: Gen 6 Legacys (and Gen 5 Outbacks) have two "oil lights" ... a "low oil level" light and a "low oil pressure" light. The "oil level" light is advisory in nature, and it's generally safe to drive a short distance until you can add oil to the engine. The "oil pressure" light is a dire warning ... permanent engine damage is likely imminent if you don't stop and address the issue NOW!

No.

I think that may not be the correct part identification for a 2016 Legacy 2.5. Edit: Per the H4 (FB25) FSM, the part in question is the oil temperature sensor, not the coolant temperature sensor. It's mounted right next to the oil pressure switch, and both share the same oil gallery just downstream of the oil filter. (N.B. There is no coolant in the timing cover.) That said, I don't know whether or not the same part number is correct for both oil and coolant temp sensors. The temperature ranges are similar, but the chemical and pressure environments are quite different.

At that rate of oil consumption, your new cat is not likely to last very long. It may be time to consider swapping out that engine. 'Till then, when was the last time you replaced the PCV valve (and hose)?

Yep. Technically, it's called a Helmholtz resonator, and there are at least two of them along the Gen 6 Legacy's intake tract, between the air filter and the throttle body. These have at least two purposes: 1) to dampen (i.e. smooth) intake airflow for better air/fuel mixture control, which may result in better fuel economy and lower exhaust emissions, and 2) to reduce engine intake noise.

The OE battery (BCI Group 25) is adequate, but marginal, for the car, IMO. Two known drop-in replacements with higher capacity are Group 34 (not 34R!) and Group 24 (not 24F!). That said, even the OE battery can sit for several weeks without going flat ... as long as the car's "dark current" demand is within spec. "Dark current" is the small amount of power the vehicle's electronic systems continue to consume even when they are "asleep." Have the seller perform a "dark current" test on the car, and let you observe the results. Per the Subaru FSM, dark current should be less than 70 milliamps (70 mA = 0.070 amps), with infrequent short bursts higher. (Most owners who have measured report that ~30 mA is actually a more typical value.) If dark current is above spec, here are some things to look for: Interior lights and/or accessories left on. A malfunctioning telematics (a.k.a. "StarLink") control module is a known cause of high dark current demand in 2016-2019 Legacys and Outbacks. Some vehicles have this problem, some never do. For Legacys with pushbutton start, leaving the fob in or near the vehicle will prevent its systems from going to sleep, with resultant high battery demand. I think the Owners Manual says at least 6 feet; 20 feet is probably safer.

You're welcome here, and you'll find that most people are generous about sharing their Subaru knowledge, but in the future ... PLEASE! ... make clear the year, model, and trim level of your vehicle. It's bad enough navigating the differences among the various Legacy/Outback years and trim levels, but you absolutely cannot assume anything about parts or wiring commonality between different model lines. (That said, the Legacy and Outback are exceptions. For any given model year they are virtually the same vehicle, except for the body aft of the B-pillar and some major suspension details.) It is highly unlikely that anything posted above applies to your 2017 Impreza, which is based on a totally different chassis platform than the Legacy/Outback. I have moved this thread to the appropriate forum and edited the title in an attempt to clarify the situation.

It would help to know the model year and trim level of your Legacy. Your fuse block appears to be mislabeled for a 2015-2019 Legacy/Outback... or at least it doesn't match the Factory Service Manual. FWIW, PU = Purge Solenoid (?), and B/UP = Backup Light (?). Neither abbreviation appears in the glossary of acronyms in the FSM. Edit: According to the 2015 Legacy/Outback FSM, that fuse is "No. 16" in the main fuse block, which is rated at 7.5 amps, is always hot, and feeds circuit "M-45." Circuit M-45 powers the battery sensor (mounted at the negative battery post) and provides keep-alive power (a.k.a. dark current) to both the ECM and TCM.

No scam here. This is common industry practice, especially in a time of rapidly rising wholesale prices and narrow profit margins. Think of it this way: Your "old" battery cost you nothing.

For someone who claims advanced automotive knowledge and experience, you have done nothing on this Forum but whine about alleged deficiencies of your Legacy. Many of your posts have seemed downright naive, and some of your reported "problems" appear to have been self-inflicted. Regardless of the reasons, your experience with the car is not typical. Clearly, the Legacy is not the car for you. Life is too short; sell it and get on with your life.

The 2015 Legacy/outback Owners Manual would be a good place to start, don't you think? Going strictly from memory, I think the 2015 3.6 had HID low beams (D4S capsule) and halogen high beams. Both are easy to replace.

You were misinformed. The warranty on the CVTs in all MY 2010-2018 Legacys and Outbacks was extended to 10 years/100,000 miles via a sequence of several TSBs. The CVT warranty for your 2017 Legacy was extended per TSB 16-115-18. Your dealer should have known that. In addition, all affected owners were notified by mail back in 2018. Regardless, I'm glad to hear that your CVT was replaced at no cost to you. TSB_16-115-18_CVT_Warranty_Extension_MY2016-2017.pdf

BS. Anecdotally, neither my 2015 Legacy nor 2016 Outback (each with ~60,000 miles on the original factory alignment) drift left or right, except perhaps in cases of unusually pronounced lateral slope of the road surface.

It will cause the regulated alternator voltage to remain at a constant 14.1-14.4 volts, which results in maximum battery charge rates. For cars that qualify (Legacy and Outback MY 2015-2016, and possibly some early MY 2017), I highly recommend the battery management firmware upgrade per TSB 11-176-17. Since the firmware is in the ECM, a dealer can do this at no charge under the 8-year/80,000 mile emissions warranty. Yes, definitely. N.B. Why guess, when you can plug a voltmeter into the accessory power outlet in the console (or into the OBD-II diagnostic connector below the dash) and monitor actual system voltage as you drive? If you don't already have a suitable meter, digital voltmeters that plug into the console power outlet are priced as low as $20 or so. Any OBD scan tool should also be able to monitor system voltage in real time.

The keys and fobs definitely use RF, but the frequencies and protocols are undocumented. Both also have embedded RFID chips to allow engine start in case the key/fob battery is depleted.

I did something similar, with a single LED strip mounted near the trunk center. Diode Dynamics in St. Louis even offers an inexpensive LED-strip kit (200 lumens) for just this purpose. Highly recommended.

Unlike the Outback, in the Gen 6 Legacy there is no such switch. The trunk light is controlled directly by the BIU. (I checked the FSM.) You can easily observe the trunk light by simply lowering one of the rear seat backs. It's a wedge-base bulb. Swing open the plastic lamp guard, and pull the lamp bulb straight down. The lamp should time out (under control of the BIU) when you close the trunk lid, but I think it will stay on indefinitely if the trunk lid isn't closed.