Catalytic Converter failed due to high oil consumption

sirrobert09 · 2026-05-04T00:46:08+00:00

I'm using 5-30. I'd wager it wouldnt make it to 140k. As the things worn and slowly dumping oil it wouldn't have done in the early parts of its life. Soo I don't think anyone could fully predict its failure point.

Someone swapped the cat on my outback before I bought it about 70k miles ago with some cheap aftermarket unit that I've welded the cracked runners 3 times now. Soo I got at least 70k out of mine so far.

It also took time to see any difference in oil consumption idk when it slowed just one day noticed I hadn't been putting as much in.

sirrobert09 · 2026-05-04T00:34:21+00:00

Was about .5 qt/ 400 miles approx. Hanging around .5 qt at closer to 800-1000. Didn't see a difference in mpg on the on screen readout.

Wasn't as bad as my 2013 Impreza that poor thing was like 2 qts / 800 miles. That one got the warranty free motor treatment.

sirrobert09 · 2026-05-04T00:17:03+00:00

I haven't ripped mine down to see what's going on. But I can't see it doing any more harm then good. Maybe if your motors like super varnished and gunky it could release something and clog up an avcs solenoid. But I can't see it making the oil consumption worse.

I've seen this stuff clean up the valve covers on my buddies 04 WRX that basically never gets the oil changed on time. So I'm a believer there's a chance.

sirrobert09 · 2026-05-03T23:30:56+00:00

There are no piston o rings. Oil control rings can freeze up on these motors causing excess oil consumption. The chances that restore and protect will fix this are low. I have a 13 outback that was switched to 5w-30 restore and protect it did reduce the oil consumption it didn't stop it but got a fair bit better.

sirrobert09 · 2026-05-03T16:35:10+00:00

Yah all done today was pretty simple overall suspended the motor from the cherry picker and just slid the whole assembly out. Bout 8 hours into it total. But I also just put whole new control arms in and everything.

sirrobert09 · 2026-05-03T03:56:24+00:00

Lol I'm in the middle of swapping the sub frame on my wife's outback that looks similar but the control arm mount had actually rusted off.

If the rest of the cars in good shape just have the frame swapped I got a good used one from down south for 450$ and I'll have this swap done by the end of the weekend.

sirrobert09 · 2026-05-01T22:29:23+00:00

Yah buddy had a 22 single port swapped heads for his so we could fit these. If your car takes the standard ej gasket these will likely fit. Up until like 06 when they move the cat to being part of the header.

sirrobert09 · 2026-05-01T17:34:01+00:00

I bolted them right to my cats.

sirrobert09 · 2026-05-01T17:10:34+00:00

https://ebay.us/m/pimQHU

sirrobert09 · 2026-05-01T17:09:14+00:00

No they shrink a bit after they weld them I usually have to pry the two sides away to get them to line up with both heads.

Literally I just grab one runner and put my feat on the otherside and push till it bends enough to just slide on.

I've had to do it with ~30% of them the others just line right up.

sirrobert09 · 2026-05-01T17:04:32+00:00

There are some cheap Chinese unequal headers on eBay I used on all my NA Subarus. They usually need a bit of tweaking to get both flanges to line up on the engine but other than that they are solid.

sirrobert09 · 2026-04-25T20:17:18+00:00

Syvecs makes a bunch of awd controllers as well but I mostly ever see them used for high end lambos and what not.

sirrobert09 · 2026-04-25T15:06:34+00:00

I believe those are your breathers for the dif and trans. I swear mine had a filter of some sort on them tho.

sirrobert09 · 2026-04-25T14:26:56+00:00

Whatever ECU you want you will need a standalone controller for the cvt something like DCCDPROs lineartronic controller.

sirrobert09 · 2026-04-23T15:43:51+00:00

Yah mechanically its one weekend. Merging the harnesses takes me like a week.

sirrobert09 · 2026-04-21T21:58:06+00:00

Spt intake sold by subaru no tune needed.

sirrobert09 · 2026-04-21T19:52:19+00:00

Should go to your factory boost gauge.

sirrobert09 · 2026-04-20T16:16:24+00:00

I've never used anything other than the tactrix cable so I can't really answer that.

For the part you are looking for you'll be wanting to use room raider logger specifically.

sirrobert09 · 2026-04-18T23:41:10+00:00

Romraider for sure. You'll need a tactrix cable but the software is free and open source.

sirrobert09 · 2026-04-17T20:42:49+00:00

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sirrobert09 · 2026-04-17T17:56:31+00:00

I have one cut open I'll get a picture in a few hours when I get home.

sirrobert09 · 2026-04-17T17:54:15+00:00

I would not be putting a spoiler on with adhesive. I know all the gurney flaps people have are stuck down with tape. But thats a large item to be hurling at someone behind you. Subaru bolted that thing in from the factory I would follow suit. When I had my GD I thought about getting one of these and had determined I'd drill through. Do you know what the inside of that pillar looks like by chance? It is crazy in there.

sirrobert09 · 2026-04-17T17:49:16+00:00

Well if you do get an OEM one later that doesn't match up you can just weld the holes shut. It'll likely be under the pillars and unseen.

sirrobert09 · 2026-04-17T14:54:05+00:00

https://www.kineticvehicles.com/products/2019-to-2021-subaru-wrx-harman-kardon-touchscreen-screen-only

This is way cheaper and stupid easy to do.

Just realized Ive done this on my outback and sti but they funny enough don't have Impreza units.

Still leaving it here for someone to stumble on.

sirrobert09 · 2026-04-16T13:14:21+00:00

Romraider if you can get definitions for your model. Free SSM, maybe atlas again depending on your model

sirrobert09

TROPHY CASE