P219B: Bank 2 Air-Fuel Ratio Imbalance

P219B is the bank 2 counterpart for V and boxer engines. Ford's 2012 summary shows one way to find it: the ECM watches the fast ripple of the bank's wide-band sensor over windows of roughly 50 revolutions and sets the code when more than 75 % of them fail, after 300 to 700 s of driving at 1000 to 3000 rpm and 20 to 60 % load. On one GM 2016 engine the bank 2 limit is 1.15 against 1.05 for bank 1. Bulletins name leaking direct injectors (Ford F-150 2.7 EcoBoost 2018; Explorer and Aviator 3.0 EcoBoost 2023 to 2025, injectors of the affected bank replaced), faulty or contaminated injectors (Honda Pilot 2016), electrical noise in the A/F sensor lines (Mazda CX-9 2011 to 2013) and, at Infiniti on the QX80, a warning not to swap the A/F sensor first. A code on bank 2 only points to a part on that side.

Bank 2 is the side without cylinder 1, so it only exists on V or boxer engines.

Symptoms

• Check engine light on
• Usually no driveability change
• Possible misfire codes on bank 2 cylinders

Most likely causes

• Leaking or contaminated injector on bank 2
• Interference or damage in the bank 2 A/F sensor wiring
• Intake runner or gasket leak at one bank 2 cylinder
• PCM calibration addressed by a software update

What to check, in order

Start with the simplest. You can tick off each step.

1. See whether the light is flashing: if so, reduce engine load and avoid driving
2. Inspect the spark plugs, coils, and connectors
3. Swap the coil with another cylinder and see if the misfire moves with it
4. Check the injector and look for air leaks
5. Run a compression test if everything above checks out

Good to know

• Repair difficulty: medium
• It affects emissions.

What each character of P219B means

• P: Powertrain: engine and transmission
• 2: Generic code: same on every make
• 1: Air and fuel
• 9B: Specific fault in that system

Frequently asked questions

Can I keep driving with code P219B?

Avoid driving if the light is flashing or the engine is shaking: unburned gasoline can damage the catalytic converter.

What causes code P219B?

The most common causes are: leaking or contaminated injector on bank 2; interference or damage in the bank 2 A/F sensor wiring; intake runner or gasket leak at one bank 2 cylinder.

Related codes

• P219ABank 1 Air-Fuel Ratio Imbalance
• P0300Random/Multiple Cylinder Misfire Detected
• P2197O2 Sensor Signal Biased/Stuck Lean (Bank 2, Sensor 1)
• P0174System Too Lean Bank 2
• P0175System Too Rich Bank 2

Sources

• newtonnet.co.uk: fordobd2012
• gsi.ext.gm.com: 16OBDG05 Engine Diagnostics
• static.nhtsa.gov: MC 11007963 0001
• static.nhtsa.gov: SB 10059455 0335

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.