I own a completely stock 2018 STI. I randomly had all 6 of these codes thrown at the same time recently.
P0011, P0021, P000A, P000B, P000C & P000D
I didn't give it much thought since the car doesn't even have 50k miles yet and it drives completely fine. I cleared the codes and yet all 6 keep coming back.
We recently had cold weather here in Texas and my power steering pump started to whine. I replaced the notorious o-ring, topped off the system and bled it. This seems to solve the problem for a week or two and then the problem comes back. The car also seems to have a hard time starting half the time.
My guess is the culprit could be the power steering pump going out thus causing enough resistance to throw the codes. This would also explain why it has difficulty starting sometimes.
I'm going check the battery to confirm the status there as well as a full oil change in case the turbos are either eating it all up or the oil is so filthy that it's clogging all of the filters/sensors.
Other likely culprits could be:
- AVCS SYSTEM - lack of oil?
- Dirty Camshaft Sensor?
- Banjo Bolt Filter Clogged
I have to think that there is only 1 or 2 problems that have to fixed here to throw all of these codes simultaneously. Any other suggestions?