Turns out it was the wastegate actuator. Some of the N20 engines use a mechanical actuator, but mine uses an electronic one. This makes sense based on what I experienced. I initially thought I blew the turbo, but was confused by the lack of smoke and the subsequent engine codes. I tested the alternator before bringing it in and it was tip top. The failing wastegate and subsequent altered A/F ratio must have set off ignition/injection alarms in the DME. I should have the car back tomorrow.

Threw a check engine light on my ‘13 X1 yesterday. 80k miles but still under the CPO warranty. Got the warning light for reduced engine power. The loss in power was noticeable, but the car sounded and ran fine. It was running normal up until the light showed up. The codes indicate some sort of electronic issue with the ignition/injectors/valvetronic/DME. The car started up fine this morning with no light and drove fine for half an hour before the light cane on again along with a reduction in power.

I’m wondering if the DME fried itself a bit or a wire deteriorated. I guess I’ll find out on Monday. My dealership has a fantastic service department and gives out free loaners. Still not sure if I’m going to keep this thing once the warranty is up. Might go back to Subaru [reaches for vape pen]. This car has actually been relatively reliable over the 50k or so miles I’ve owned it. It has onky needed an AC condenser and a coolant resevoir in that time. It sounds like a diesel (N20 life) but only burns 1/2 quart of oil every 5k miles and gives me 35ish mpg on the highway (when taking it easy) with 250 ponies on tap.