2011 wrx Subaru really bad idle

So I was driving home on the freeway and everything seemed normal, down shift for slow traffic when I hit the gas I heard a extremely loud pop My oil light flashed a couple times then the car died. I limped it off the free to a parking lot to tow it home. Checked for broken or lose hoses found the pcv hose to the crankcase was broken replaced that and it still idles like crap and makes 0 power.

All factory or some mods?

Completely factory, never really had the urge to put any mods, only 30k miles on her too

A loud bang like that can be caused by the engine misfiring which sends raw gasoline into the exhaust system, which explodes inside the exhaust pipe/cat/muffler, wherever and you hear a loud bang. This can also damage the exhaust system, which might be the cause of your poor idling. Another idea, some sort of problem with the ignition or valve timing, and the bang was cause b/c an intake valve opened at he time the spark happened. That bang would have come from the intake manifold, which could also have damaged something. Is this engine turbo-charged?

Where I’d start – besides checking for diagnostic codes — is to examine the exhaust system for broken joints, and the intake manifold area for something that has come loose, especially any rubber boots between the air filter and the throttle body. My wild guess, and just a guess, is the valve timing has changed for some reason, some problem with the timing chain system. EGR , fuel pressure, intake manifold vacuum, and cylinder compression tests might be needed too.

Compression test is definitely on my list to do, of course the codes it has is p2433 secondary air injection air flow/ pressure sensor circuit high bank 1, p0113 intake air temperature sensor circuit high input and p050a cold start idle control system performance. And well a misfire in 2.

Inspect the turbo and intercooler pipes and connections, something may have ruptured or come loose.

Only thing I’ve seen was the hose from the intercooler to the intake manifold was loose alittle got those tight and it hasn’t changed anything

what is vacuum reading at idle?

Good idea w/a misfire on 2 code to remove & inspect the number 2 spark plug and its coil. There’s probably a relatively easy to do resistance test on the coil, if you can find the procedure. While in the area check out the injector’s wiring & connector for any signs of problems. The codes definitely seem to be related to the turbo. But that might be a symptom, not the cause.

AFAIK Subaru is not using individual coil packs, it is one block for all 4 cylinders, firing two of cylinders at once.
It is possible that coil pack or wire or extension boot could develop a carbon track “shorting” high voltage.
If one is lucky enough, a visual inspection would show a faint path of the traveling spark in this case.
I happen to have two occurrences of high voltage carbon-tracking over wire boots in 5 Subies I used to own, so I would start there.

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