P0174 is a diagnostic trouble code that indicates a problem with the fuel system in Bank 2 of the engine. Specifically, it means that the fuel system is running too lean, indicating that there is too much air and not enough fuel being delivered to the engine.

There are a few potential causes for a P0174 code. One possibility is a vacuum leak, where un-metered air is entering the intake system. This can be caused by a cracked or damaged vacuum hose, a faulty intake manifold gasket, or a loose connection.

Another possible cause is a malfunctioning mass airflow (MAF) sensor. The MAF sensor measures the amount of air entering the engine and sends this information to the engine control unit (ECU), which then adjusts the fuel delivery accordingly. If the MAF sensor is dirty or faulty, it can provide inaccurate readings, causing an imbalance in the air-fuel mixture.

A third potential cause is a problem with the fuel delivery system. This can include a clogged fuel filter, a weak fuel pump, or injectors that are not spraying fuel properly. Inadequate fuel pressure or volume can result in a lean condition.

It's worth noting that the P0174 code specifically refers to Bank 2 of the engine. This means that the issue is likely isolated to one half of the engine, rather than affecting both sides equally.

To diagnose and fix the issue, you can start by visually inspecting the vacuum lines and hoses for any signs of damage or disconnection. You can also clean the MAF sensor using a specialized cleaner to see if that resolves the problem.

If the issue persists, further testing might be required. This can involve checking the fuel pressure to ensure it meets the manufacturer's specifications, inspecting the fuel injectors, or using a diagnostic tool to assess the functioning of the engine sensors and the ECU.

It's important to address a P0174 code in a timely manner, as running the engine too lean can cause damage to other components, such as the catalytic converter. If you're not confident in diagnosing and repairing the issue yourself, it's advisable to take your vehicle to a qualified mechanic for further inspection and repair.