Engine Code P219A

Hello,

P219A- air/fuel ratio imbalance bank 1.

Bank 1 is the right bank, passenger side.

This imbalance can be caused by a number of different malfunctions including but not limited to:
†Exhaust Manifold to Cylinder Head leak at a specific cylinder.
†Intake Manifold leak at a specific cylinder.
†Fuel Injector problem.
†Variable cam lift failure.
†Camshaft/ Valvetrain problems.
†Ignition system problems at a specific cylinder.
†Engine mechanical problems relating to cylinder combustion at a specific cylinder.

The Cylinder Imbalance Detection requires that the Upstream Oxygen (O2) Sensors are capable of operating at high frequencies, since an aged O2 Sensors response capability at a higher frequency range can be degraded. Therefore, before this monitor can become active, the O2 Sensor High Frequency Response monitor is performed to see if the sensor is even capable of detecting an imbalance.

Once active, the Cylinder Imbalance Detection monitor matches up the Upstream O2 Sensor signal with the corresponding cylinders on that bank. Each cylinder is monitored, and adjustments are made as needed for each cylinder to correct an air/fuel ratio imbalance. If an individual cylinder reaches a calibrated adaptation threshold (15%), the diagnostic monitor will be considered failing.

Possible Causes.

INTAKE MANIFOLD LEAK AT A SPECIFIC CYLINDER ON BANK 1
FUEL INJECTOR ISSUES AT A SPECIFIC CYLINDER ON BANK 1
IGNITION SYSTEM ISSUES AT A SPECIFIC CYLINDER ON BANK 1
CYLINDER COMPRESSION IMBALANCE
CARBON BUILD UP
VARIABLE VALVE TIMING ISSUES
VALVE TRAIN ISSUES

Suggest to first swap the upstream oxygen sensor from bank 2 to bank 1.
If your mechanic has smoke tester, I would suggest to smoke test the intake system and check for leaks, see image below.

How to check for a vacuum leak.
https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

A good video.
https://youtu.be/TmV_HjeiuCc

Hope this helps.

Cheers, Boris