Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the engine's computer has found that the air and fuel mixture in cylinder 6 is not right. There is too much air and not enough fuel, which can make the engine run poorly.
The engine control module (ECM) monitors the air-fuel ratio in each cylinder. If it detects that the mixture in cylinder 6 is too lean (more air than fuel), it triggers this code.
The P11DA code indicates that the ECM has detected an imbalance in the air-fuel ratio for cylinder 6, specifically that the mixture is too lean. This can be due to issues such as a malfunctioning fuel injector, vacuum leaks, or problems with the oxygen sensor.
• Check Engine Light is on
• Rough idle
• Poor fuel economy
• Engine misfire
• Loss of power
• Faulty fuel injector in cylinder 6
• Vacuum leak near cylinder 6
• Defective oxygen sensor
• Fuel pressure issues
• Exhaust leak near the cylinder
ECM: Engine Control Module, the computer that controls engine functions.
Lean Condition: A situation where there is too much air and not enough fuel in the air-fuel mixture.
• Use an OBD-II scanner to confirm the code.
• Inspect the fuel injector for cylinder 6.
• Check for vacuum leaks around cylinder 6.
• Test the oxygen sensor's functionality.
• Measure fuel pressure to ensure it's within specifications.
• Replace or clean the fuel injector for cylinder 6.
• Repair any vacuum leaks found.
• Replace the faulty oxygen sensor.
• Fix any exhaust leaks.
• Adjust or replace the fuel pressure regulator if needed.
• OBD-II scanner
• Fuel pressure gauge
• Vacuum leak detector
• Multimeter
• Basic hand tools
$150 - $500
Moderate
• Chevrolet Silverado
• GMC Sierra
• Cadillac Escalade
• Regular maintenance of fuel injectors.
• Check and replace air filters periodically.
• Inspect and maintain oxygen sensors.
Engine Performance
• Have the vehicle inspected by a professional mechanic.
• Avoid prolonged driving with this code active to prevent engine damage.
Check with the vehicle manufacturer for warranty coverage on emissions-related components.
This code has been associated with vehicles that have high mileage or lack of regular maintenance, particularly in fuel system components.
Moderate – While the vehicle may still be drivable, it's important to address this issue to prevent further engine damage.
Driving with a lean condition can lead to increased emissions and potential engine damage, which may not comply with emissions regulations.
• Engine at operating temperature
• Vehicle in closed-loop fuel control
Cylinder 6 is typically located at the rear of the engine on the driver's side in a V6 or V8 engine layout.
Q: Can I drive with a P11DA code?
A: It's possible to drive short distances, but it's best to fix the issue soon to avoid engine damage.
Q: Will a P11DA code cause my car to fail emissions tests?
A: Yes, a lean condition can increase emissions and cause the vehicle to fail emissions testing.
High-End · Full-system diagnostics
A full-system bidirectional platform aimed at advanced DIY users and professional diagnostic workflows.
Network faults often require full-system access instead of a generic code reader alone.
View on Amazon
Universal · Digital multimeter
A solid entry-level multimeter for voltage, continuity, resistance, and basic electrical troubleshooting.
Helpful for checking voltage drops, grounds, and basic circuit health when modules are not communicating.
View on Amazon
Universal · Wire connectors and repair kit
Useful when diagnosis points toward damaged wiring, corroded terminals, or connector repairs.
Useful if diagnosis points toward damaged connectors, wiring, or terminal repairs.
View on AmazonThese are optional diagnostic tools, not guaranteed fixes. As an Amazon Associate I earn from qualifying purchases.
Fitment Required · Vehicle-fitment part
Relevant when the code or supporting diagnostics point toward upstream or downstream oxygen-sensor faults.
This code family often involves upstream or downstream oxygen-sensor diagnosis.
Verify exact sensor position and vehicle fitment before buying.
View options on Amazon
Fitment Required · Vehicle-fitment part
Commonly relevant for misfire, ignition-efficiency, and some drivability-related repairs.
Misfire and ignition-related faults commonly involve spark plugs as part of the repair path.
Check the correct plug type, gap, and engine application for your vehicle.
View options on Amazon
Fitment Required · Vehicle-fitment part
Relevant when the fault points toward ignition-coil performance or cylinder-specific ignition issues.
Some ignition faults involve coil performance or cylinder-specific coil problems.
Match the coil to your engine and confirm the failed component before ordering.
View options on AmazonThese parts may be related to this fault category, but a code by itself does not confirm exact fitment or guarantee that replacing a part will solve the problem.