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 car's computer has detected a problem with how the intake valve for cylinder 4 is working. It's like if one of the doors in a house isn't opening and closing properly.
The code indicates an issue with the performance of the intake valve or the deactivation mechanism for cylinder 4. This can affect how the engine runs.
P349B is triggered when the Engine Control Module (ECM) detects that the intake valve for cylinder 4 is not performing as expected. This could be due to a mechanical issue with the valve, a problem with the deactivation solenoid, or an issue with the valve timing.
• Engine misfire
• Reduced fuel efficiency
• Check Engine Light on
• Faulty intake valve
• Malfunctioning cylinder deactivation solenoid
• Valve timing issue
ECM: Engine Control Module
OBD-II: On-Board Diagnostics II
• Use an OBD-II scanner to confirm the code.
• Inspect the intake valve and deactivation solenoid for cylinder 4.
• Check for any issues with valve timing.
• Replace faulty intake valve.
• Repair or replace the deactivation solenoid.
• Adjust or repair valve timing.
• OBD-II scanner
• Wrench set
• Valve timing tools
$200 - $600
Moderate
• Honda Accord
• Chevrolet Silverado
• Ford F-150
• Regular engine maintenance
• Timely oil changes
• Use quality fuel
Engine Performance
• Avoid driving aggressively until the issue is fixed.
• Schedule a repair appointment as soon as possible.
Check with your vehicle manufacturer for warranty coverage related to engine components.
This code has been more common in vehicles with cylinder deactivation technology.
Moderate – It should be addressed soon to prevent further engine damage.
Ignoring this code may lead to increased emissions and potential engine damage.
• Engine at operating temperature
• Vehicle in idle or light load conditions
The intake valve and deactivation solenoid for cylinder 4 are located in the engine's cylinder head.
Q: Can I drive with a P349B code?
A: It's not recommended to drive for extended periods with this code, as it can lead to engine damage.
Q: How do I reset the P349B code?
A: You can reset the code using an OBD-II scanner, but it's important to fix the underlying issue first.
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
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.