Numbchux

Well, small update. She had the fluid changed at a local-to-her independent shop that she frequents, she brought in Subaru CVTF A few days later, she was driving, and noticed a loss of power on the highway, and when she pulled over, the engine had stalled. She had to navigate across a lane of traffic and an entrance ramp, so she's not sure if it stalled on the move, or when she stopped (like a stuck torque converter). But, after cycling the key, it started back up, and drove normally. My dad read the codes later that day, and found P0700 (AT abnormal) and P0841 again. She's visiting me again this week. First thing I found out, none of my scan tools will read the live data for that sensor. I have a Carista ELM327 bluetooth adapter that I use with my phone, I have a couple basic apps, but ActiveOBD is a Subaru specific one, with which I can read torque converter lockup, AWD transfer, transmission temp and more. I also have an Innova 3170RS, and FreeSSM. So, then I was left with the options to buy a better tool to test it. Pay the dealership to test it. Or, just throw the $150 sensor in. The local dealership had it on the shelf, and said they use them in the shop about once a month. If it were my car, and only driven locally, I'd drive it and wait for symptoms to worsen. But it's my mom's, and she drives all over the state, a breakdown in the middle of nowhere would be far more costly. So, I did what I hate to do, and loaded up the parts cannon. Yesterday I put 5 more quarts of Subaru CVT fluid in (what came out was still pretty brown) and the secondary pressure sensor. With such intermittent symptoms, only time will tell if that was the chicken or the egg. I drove it to work today, and it's showing it's age. Not sure what the future is for this car, it seems like a pretty nice car, but with a salvage title, considerable oil consumption, and a failing CVT, it's probably not worth much, and not worth fixing.

small clarification In the late '90s, they transitioned to a single 3-wire sensor, which still performed like 2 separate sensors (2 wires for the ECU, single wire resistance-to-ground for the gauge). And then around 2008, they transitioned to a single 2-wire sensor only feeding the ECU, which then outputted a signal via CAN to the gauge cluster. Yep, you can use your EA81 sending unit with a little modification. Or you can wire a resistor in to modify the EJ signal for the EA dash (I know this works on the EA82s, I think the EA81s as well). That's in my write-up. Or, just wire the EJ sensor to the EA gauge, and it will read about 1/2 what it used to, but will still give you some information.

http://opposedforces.com/parts/info/11044AA483/ https://www.ebay.com/itm/192453951693 both list SOHC non turbo and turbo 2.0 applications. That's what I would use. USDM source, lists WRX EJ205 https://www.subarupartsdeal.com/parts/subaru-gasket-cylinder-head~11044aa483.html

I know STi turbo head gaskets are used on the SOHC 2.5 all the time, I would think WRX would be the same. Timing change would be negligible, compression might be noticeable.

WRX 2.0 head gasket should work just fine. Everything else is the same as SOHC 2.5. Very easy to get parts with that little bit of information.

use your VIN on the parts site, it'll only give you one option. Or, look at the plate on the LH strut tower in the engine bay for the original complete engine code.

If anyone has any insight, or, I'll just document what I find in case someone is looking in the future. My mom's 2012 Impreza 2.0i Premium. 216k miles, original engine and CVT. Had the torque converter solenoid fail last summer, and the fluid was a bit brown, so I did a drain and fill then (probably 190k miles), and we did another at about 80k, when I was working at a dealership. The AT Oil Temp light was flashing one day, I scanned it about 2 days later (no lights on) and it had a stored P0841, as well as a U0100 (CAN signal error), C1431 (AT abnormal), and C1422 (VDC Interrupted). From the Subaru FSM: First 2 steps in the diagnostic procedure is to check the condition and level of the CVT fluid. I think she's going to have another drain and fill done (she does not live locally to me, so I probably won't see the car for another couple weeks). And then there are a few tests using the SSM to check the pressure readings from the sensor under a few conditions (Idle in park, 3k rpm in park, torque convert stall at WOT). Beyond a fluid related issue, the procedure basically ends with the sensor, wiring, or transmission causing the fault. The secondary pressure sensor is externally mounted, threaded in towards the rear of the left side of the transmission. By her VIN, part #31878AA020, with an MSRP of $148.17

I don't quite follow what you're doing. But, the low range gearset is on the input shaft of the transmission. The EJ cases are cast with the cavity for the gears, but they are not machined out for the bearings and such. It would take quite a bit of precision machining to convert a single range case to dual. The 4WD versions have a very different output shaft/front pinion arrangement. You could use a FT4WD front pinion gear in an EJ output shaft, and then have the locking center. But if you don't care about unlocking, it would be far easier to just weld the EJ center.

The fact that it's felt in the steering wheel has me thinking it's not the transmission. I just replaced a CV axle with a completely failed inner joint, and it could not be felt in the steering wheel any more than anything else (it shook the whole car....). I've been chasing this vibration for years, and because it wasn't felt in the steering wheel, didn't even occur to check the front axles. Boot was fine, and it only happened once driven at least a few miles. Does it change at all when on or off throttle? Brakes? Pull to one side more than the other?

That's puurrrrdy

The ECU, and emissions system in the car is not expecting an EGR. So you are just keeping it factory. Blocking off EGR on a system that had it is different.

Yep, Take the wire off the starter solenoid and run it to trigger the relay.

I've put a hot shot relay in a couple subarus with no trouble. As long as it's triggered by the factory switch, it should all be fine. The system doesn't know if it's directly triggering the starter solenoid, or a relay. It's possible that the original problem was a failing neutral/range switch or wiring to it, and you are now getting a second symptom.

Should be a yellow tag on a battery cable with instructions. But yes, if the battery is disconnected, the parking lights will flash. Ignition "ON" and press that button for 1 second resets it.

A lot of variables. Be more specific with your questions, and you will get more specific answers. All EJ engines share essentially the same basic dimensions. So they will all physically fit almost identically (with the exception of the last few years of the EJ253, 2010-2012 or so, where the motor mount configuration changed a bit). 2.2s were made 1990-2001. So the difference comes in the electronics, which can be changed. But ASSuming you want to use the ECU and wiring from your donor car (cheapest option), the rule of thumb, is the older ones are simpler, and the newer ones are more complex. 1995 (for the 2.2) added OBDII, which makes them far more easy to diagnose, as any off the shelf code reader can connect to it. But much newer than that adds fuel tank sensors and stuff that will be hard to replicate/bypass in the new chassis, so you will likely always have trouble codes.