P0174: System Too Lean (Bank 2)
Can you still drive? Yes, but prolonged lean operation can cause engine overheating and potential piston or valve damage.
What Does P0174 Mean?
Code P0174 is the bank 2 equivalent of P0171, indicating that the engine control module has detected a lean air-fuel mixture on bank 2. If both P0171 and P0174 are present simultaneously, the issue likely affects both banks equally, pointing to a common cause such as a failing fuel pump or large vacuum leak.
Need to read your codes?
An OBD-II scanner lets you read and clear diagnostic trouble codes from your vehicle's computer. Most scanners work with any car made after 1996.
Browse OBD-II Scanners on AmazonCommon Causes
- Vacuum leak on bank 2 side of intake
- Faulty mass airflow sensor
- Low fuel pressure from weak fuel pump
- Clogged fuel filter
- Leaking intake manifold gasket on bank 2
Symptoms
- Check engine light on
- Rough idle
- Hesitation during acceleration
- Poor fuel economy
- Possible stalling
Diagnostic Steps
- 1Check fuel trims for bank 2 with scan tool
- 2Perform smoke test for vacuum leaks on bank 2
- 3Test fuel pressure at the fuel rail
- 4Clean or replace mass airflow sensor
- 5Inspect intake manifold gaskets
- 6Check for cracked vacuum hoses on bank 2 side
Recommended Parts & Tools
mass airflow sensor
intake manifold gasket set
Estimated Repair Cost
| Type | Estimated Cost |
|---|---|
| Total Repair Cost Range | $75 - $1200 |
Get a Personalized AI Diagnostic Report
Get a detailed AI diagnosis for code P0174 specific to your vehicle. Includes step-by-step repair instructions, exact parts needed, and a cost breakdown tailored to your make and model.
Chat with AI About P0174Commonly Affected Vehicles
Related Recalls
1 Active Recall — 2026 Ford F-150
The following NHTSA safety recalls have been issued for this vehicle. Contact your dealer to check if your vehicle is affected.
ELECTRICAL SYSTEM: INTEGRATED TRAILER BRAKE CONTROL
Ford Motor Company (Ford) is recalling certain 2021-2026 F-150, 2022-2026 F-250 SD, F-350 SD, F-450 SD, F-550 SD, Maverick, 2024-2026 Ranger, 2023-2026 F-600 SD, 2022-2027 Lincoln Navigator, Expedition, and 2026 E-Transit vehicles. When towing a trailer, the integrated trailer module (ITRM) may lose communication with the vehicle, possibly causing a loss of brake and turn signal lights, or a loss of brake function. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 108, " Lamps, Reflective Devices, and Associated Equipment."
Remedy: The integrated trailer module software will be updated by a dealer, or through an over-the-air (OTA) update, free of charge. Owner notification letters are expected to be mailed March 17, 2026. Owners may contact Ford customer service at 1-866-436-7332. Ford's number for this recall is 26C10. Vehicle Identification Numbers (VINs) involved in this recall will be searchable on NHTSA.gov beginning March 17, 2026.
Data provided by the National Highway Traffic Safety Administration (NHTSA).
Frequently Asked Questions
What does bank 2 mean?
Bank 2 refers to the side of the engine opposite cylinder 1. On V6 and V8 engines, each side is considered a separate bank with its own fuel trim adjustments.
Why do I have both P0171 and P0174?
When both codes are present, the cause likely affects both banks equally. Common causes include a failing fuel pump, clogged fuel filter, or contaminated MAF sensor.
Community Fix Reports
Community reports are user-submitted and not verified by Auto AI Buddy. Results may vary.
Related Codes
Affiliate Disclosure: This page contains affiliate links. If you purchase products through these links, we may earn a small commission at no additional cost to you. This helps us maintain this free resource. We only recommend products we believe will help you diagnose and repair your vehicle. Prices shown are estimates and may vary.