P219B Code: Bank 2 Air-Fuel Ratio Imbalance
One cylinder on bank 2 runs off the mixture of the other cylinders on that side of the engine.
At a glance
Severity: Moderate
- Meaning
- Bank 2 Air-Fuel Ratio Imbalance
- System
- Fuel & Air Metering · Powertrain
- Safe to drive?
- With caution
- Typical repair cost
- $40–$1,000
- DIY difficulty
- Hard
P219B is the bank 2 version of the cylinder imbalance monitor, so it only exists on engines with two monitored banks: V6, V8 and V10 engines, flat-sixes and some inline-sixes with split exhausts. The Bank 2 upstream air-fuel sensor is seeing a repeating spike from one cylinder whose mixture doesn't match the rest. The first thing to establish is whether P219A is stored too. If both banks report imbalance, look for something every cylinder shares, like carbon on direct-injection intake valves, fuel pressure problems or poor fuel. If only bank 2 is flagged, the fault sits on that side: an injector, an intake runner leak, a valve issue, or even an exhaust leak at one exhaust port that pulls air in with that cylinder's pulses. Bank 2 injectors are often under the intake plenum, so a correct diagnosis before tearing down saves real labor.
Can I keep driving? Usually drivable, but one bank 2 cylinder is burning the wrong mixture and emissions are up. Avoid towing and long full-load runs, and stop driving if the check engine light flashes or a misfire becomes noticeable.
How to read P219B
- P Powertrain
- 2 Generic (SAE)
- 1 Fuel & air metering
- 9B Specific fault
Symptoms
- Check engine light, sometimes with no other complaint
- Faint shake at idle, more noticeable with the A/C on
- Misfire code on one bank 2 cylinder now and then
- Ticking from one exhaust port if an exhaust leak is involved
- Slightly higher fuel consumption
Possible causes
Ranked by how often each cause is behind this code (editorial estimate).
- One bank 2 injector restricted, leaking or with a poor connector
- Intake leak at a single bank 2 runner, including a vacuum port (booster, PCV) that feeds one runner
- Exhaust leak at one bank 2 exhaust port pulling air in with that cylinder's pulses
- Valve problem on one bank 2 cylinder: carbon, burnt valve, worn lifter
- Shared cause across both banks (DI intake valve carbon, fuel pressure) when P219A is also set
- Weak ignition coil or plug on one bank 2 cylinder
- Bank 2 air-fuel sensor slow or aged
Diagnosis step by step
One bank or both?
If P219A and P219B are both stored, start with shared causes: fuel pressure, fuel quality and, on direct-injection engines, intake valve carbon. P219B alone sends you to the individual cylinders on bank 2.
Tools: OBD-II scanner
Find the odd cylinder
Compare Mode 6 misfire counts for the bank 2 cylinders, then read their spark plugs side by side. The plug that is noticeably whiter (lean) or sootier (rich) than its neighbors usually marks the cylinder.
Tools: OBD-II scanner, Spark plug socket
Measure injector resistance before teardown
Back-probe each bank 2 injector connector: typical high-impedance port injectors read around 12–16 Ω, and all injectors on the engine should be within about 1 Ω of each other. An outlier or a loose, corroded connector can be fixed without removing the plenum.
Tools: Multimeter
Check ports that feed a single runner
Smoke-test the intake and pay extra attention to vacuum fittings tapped into one runner, such as the brake booster or PCV connection. On a cold start, listen along the bank 2 exhaust manifold for a tick at one port.
Tools: Smoke machine, Flashlight
Confirm with compression or injector swap
Run a compression and leak-down test on the suspect cylinder. If mechanics are fine, swap its injector with a neighbor on the same bank; if the problem moves, the injector is bad.
Tools: Compression tester, OBD-II scanner
Where the parts are
- 1Ignition coil
- 2Spark plug
- 3Fuel injector
- 4Camshaft sensor
- 5Crankshaft sensor
- 6Engine computer (ECM)
- 7Intake manifold
Repair options & costs
| Repair | DIY? | Estimated cost |
|---|---|---|
| Repair or replace a bank 2 injector connector | Yes | $40–$150 |
| Replace one bank 2 injector (plenum removal) | No | $300–$800 |
| Replace bank 2 exhaust manifold gasket | No | $250–$800 |
| Clean intake valve carbon on both banks (DI) | No | $500–$1,000 |
| Replace ignition coil and plug on one cylinder | Yes | $120–$300 |
Rough US estimates for parts and labor; shop rates vary by region. Not a quote.
Notes by brand
Field data
| Honda | 16 | Pilot, Odyssey | |
|---|---|---|---|
| Jeep | 2 | Grand Cherokee, Wrangler Unlimited |
Source: NHTSA Complaints API (US government open data), analyzed by DTC mention.
Emissions / smog test impact
Will fail
P219B with the check engine light on fails the OBD-II test. The imbalance monitor reruns only during steady cruising, so after the repair drive some highway miles before the retest.
Frequently asked questions
What does it mean if I have P219A and P219B together?
When both banks show imbalance, one cylinder going bad on each side at the same time is unlikely. Look for something all cylinders share first, such as fuel pressure, contaminated fuel or carbon on direct-injection intake valves.
Can an exhaust leak cause an imbalance code?
Yes. A leak right at one exhaust port lets outside air in during that cylinder's exhaust pulse. The air-fuel sensor then sees one lean spike per cycle, which looks exactly like a lean cylinder.
Why is the repair so expensive on my V6?
On many V engines the bank 2 injectors sit under the upper intake plenum, so replacing one means removing the plenum and fitting new gaskets. That's why testing resistance, connectors and leaks first is worthwhile.
Sources
- SAE J2012 – Diagnostic Trouble Code Definitions
- ISO 15031-6 – Road vehicles, diagnostic trouble code definitions (EOBD)
- US EPA – On-Board Diagnostics (OBD) program
- Manufacturer public service information (cross-checked)
- NHTSA Complaints API
- Methodology: How We Build Code Pages · Data Sources We Use · Editorial Policy