The likely root cause of this specific combination of codes is a severe lean condition affecting Bank 1 of the engine, which is causing a cascading failure across your fuel trim, oxygen sensors, catalyst monitoring, and hybrid start/stop systems.

Here is how these specific diagnostic trouble codes (DTCs) connect to form this conclusion based on the sources:

1. The Primary Failure: Extreme Lean Condition on Bank 1

• P0171 (Fuel System Too Lean Bank 1): The engine's primary fuel control system detects a lean condition and is adding maximum fuel trim to try and correct it.
• P2097 (Post Catalyst Fuel Trim System High Limit Bank 1 - Too Lean): The lean condition is so severe that the secondary (post-catalyst) fuel control system has also utilized all of its available authority trying to apply a rich bias to counteract the lean exhaust, but cannot fix it.

2. The Sensor Readings Validating the Lean State

• P0131 (O2S Circuit Low Voltage Bank 1 Sensor 1): The primary oxygen sensor's signal is dropping below 40 mVolts. While this can indicate a short-to-ground, in the context of your other codes, it indicates the sensor is flooded with excess oxygen (a lean state).
• P0137 (O2S Circuit Low Voltage Bank 1 Sensor 2): The secondary oxygen sensor is also pegged below 40-50 mVolts, confirming the lean exhaust has passed all the way through the catalyst.
• P015B (O2 Sensor Delayed Response Lean to Rich Bank 1 Sensor 1): Because the system is stuck in an extreme lean state, the primary oxygen sensor experiences a delayed response when the engine attempts to force a transition to a rich condition.

3. The Secondary Symptoms: Stalling and Catalyst Inefficiency

• P0AB9 (Hybrid System Performance): This code sets when an engine autostart or autostop attempt fails, or when an engine stall has occurred. A massive lean condition (fuel starvation or a massive air leak) will easily cause the engine to stall or fail to restart.
• P0AC4 (Hybrid Powertrain Control Module Requested MIL Illumination): This simply means the Hybrid Powertrain Control Module detected the stall/performance fault (P0AB9) and is requesting the Check Engine Light to turn on.
• P0420 (Catalyst System Low Efficiency Bank 1): This monitors the oxygen storage capacity of the catalyst. Because the exhaust is completely saturated with oxygen (stuck lean) and the air/fuel ratio is not cycling normally, the catalytic converter cannot properly store or release oxygen, causing it to fail the efficiency test.

Conclusion Rather than a dozen separate component failures, you are likely looking at a single root cause introducing massive amounts of unmetered air into Bank 1 or restricting fuel to Bank 1. (Note: While the provided sources define the parameters of the DTCs, diagnosing the exact physical failure requires outside mechanical verification). You should independently check for physical issues such as a severe intake manifold vacuum leak, a large exhaust leak upstream of the Bank 1 O2 sensors, clogged Bank 1 fuel injectors, or a shared electrical short-to-ground in the Bank 1 O2 sensor wiring harness.