any update on this? Mine is a 2016 and it does the same thing. I can clear the code and it will come back, usually when driving normal. it also hesitates or isn't smooth when accelerating at/over around 4k rpm's when you pass someone.

 

A likely culprit in your case might be the Variable Valve Timing (VVT) system, especially with the way you describe the inconsistencies in acceleration and the exhaust popping. Issues such as a failing VVT sensor, a malfunctioning camshaft timing actuator, or even low oil levels can disrupt the VVT’s operation, causing the timing to be off and ultimately your performance to suffer. It's also worth checking for any timing chain or belt issues, as slack in the timing assembly can lead to erratic valve operation. Additionally, consider the possibility of a faulty MAP (Manifold Absolute Pressure) sensor, which could misread the engine’s load, affecting air-fuel mixture and performance.
To properly diagnose the issue, I highly recommend running a full system scan—that's probably your best next move. A detailed scan will give insight into any additional codes that may not be directly related to the P000B. Be mindful to avoid basic OBD-II scanners like the Actron CP9190, which only provide engine codes, leaving out crucial information from systems like the VVT control module or others that could relate to your symptoms. Utilizing a full system scanner will not only help you catch those hidden codes but also give you a better understanding of all the modules at play. Personally, I rely on the youcanic full system scanner for diagnostics because it can execute a QuickScan and reveal all stored and current fault codes across various control modules. Have you checked your oil level and condition recently? Low oil levels can often affect VVT operation.

 

Thanks for some additional insight. I'm coming from k-series where you could basically drain all the oil out, flip it over, and run it for another 100k miles. The fa20 is definitely a different beast. The oil level is good, oil is clean. I switched cam shaft sensors side for side. In mine. The code doesn't come back right away, it might stay off for days or weeks. I switched the sensors to see if the problem moves to the drivers side. For what it's worth, both sensors had a build up on them, similar to what you might find on a magnetic oil plug, if that makes sense? The car just rolled over 72k miles but I think it's been opened up before. Subaru probably doesn't use red/orange rtv for the front cover, right? It all looks uniform and professional, just looks out of place but I'm not super familiar with these engines yet. I'll look into your suggestions. So far, after cleaning and swapping sensors the car seems to speed up more smoothly when on the highway. Like I said, it may just be a learning curve too. K-24 na linear power vs the more not much(still more than the k24) and then everything of the fa20 when in boost. Also, DAM is stays at 1 and fine knock learn will occasionally go to 1.41 or whatever but I haven't been able to pinpoint when, it must happen so fast, then back to 0.

 

Buildup sounds like oil changes were cheap or not enough. These engines are a lot more sensitive to oil than Ks and Bs. Long term, a high quality low SAPS oil, ACEA C2/C3 at 5kmiles/1year should reduce buildup. At that mileage intake valve cleaning and engine flush will help clear buildup elsewhere. Spark plugs and pcv valve are probably due for replacement.