System Too Lean (Bank 2)
The engine is getting too much air or not enough fuel on bank 2. This can happen from a vacuum leak, a bad MAF sensor reading, or a fuel delivery problem.
You can usually drive short distances, but the problem should be fixed soon. A lean condition can cause rough running, misfires, poor performance, and possible engine damage if ignored.
P0174 means the PCM has detected that bank 2 is running lean, meaning the measured air-fuel mixture contains too much air and not enough fuel. The code is set when fuel trims on bank 2 stay excessively positive as the PCM tries to add fuel to correct the condition.
Bank 2 is the side of the engine that does not contain cylinder 1 on V-type engines. On many inline engines, this code may not apply because there is only one bank.
Yes. A vacuum leak is one of the most common causes because extra unmetered air makes the engine run lean.
Yes. If the MAF sensor underreports incoming air, the PCM may command too little fuel and set a lean code.
Yes. Dirty or restricted injectors can reduce fuel delivery and create a lean condition.
Yes. A weak fuel pump or clogged fuel filter can reduce fuel supply enough to trigger this code.