P2006
Universal (All Makes) Vehicle (OBD-II)
Severity:What Does This Error Mean?
P2006 means the Intake Manifold Runner Control (IMRC) is stuck in the closed position on Bank 1. Unlike P2004 (stuck open), stuck closed prevents the high-RPM airflow needed for power. This can cause significant power loss at highway speeds or under heavy acceleration. You may feel the car struggling above 3,000 RPM as if it hits a wall. Carbon fouling is the most common cause on high-mileage engines.
Affected Models
- Common in Ford F-150, Mustang, and Explorer with V6/V8
- Common in Ford Escape, Edge, and Fusion with 2.5L to 3.5L engines
- Common in Mazda 6 and CX-9 sharing Ford platform
- Seen in Lincoln MKX and MKZ
Common Causes
- IMRC butterfly valve stuck closed due to carbon buildup in the intake manifold
- Broken IMRC actuator linkage rod that can no longer open the valve
- Failed IMRC actuator motor unable to generate enough force to move the valve
- Manifold runner vacuum system fault preventing the actuator from operating
- Damaged wiring or connector preventing the actuator from receiving control signal
How to Fix It
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Check for carbon buildup by removing the intake air duct and looking inside the throttle body opening.
Heavy carbon coating visible on the throttle plate and intake walls indicates likely IMRC carbon fouling.
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Inspect the IMRC actuator linkage rods visually — look for broken or disconnected rods on the intake manifold.
A broken linkage rod is a common, visible failure that is easy to confirm without any testing.
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Attempt to manually move the IMRC butterfly valves by hand with the engine off. They should move freely.
If the valves are stuck or very stiff, carbon removal is needed before anything else.
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Clean the IMRC valves using carburetor cleaner spray. Apply it to the valve edges and work the valves back and forth.
Soaking stubborn valves with cleaner and waiting 10 to 15 minutes before working them often helps.
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If cleaning frees the valves, clear the code and test drive at highway speeds to confirm the repair.
Replace the IMRC actuator if the valves move freely but the code returns — the actuator may be too weak to operate them under load.
When to Call a Professional
Intake manifold cleaning by a shop runs $150 to $300. IMRC actuator replacement is $30 to $100 in parts plus 1 to 2 hours labor. Full intake manifold replacement (if runners are cracked) is $300 to $700. DIY cleaning is very doable with basic tools and carburetor cleaner.
Frequently Asked Questions
How does P2006 (stuck closed) differ from P2004 (stuck open)?
P2004 (stuck open) mainly affects low-RPM efficiency and idle quality. P2006 (stuck closed) mainly hurts high-RPM power output — you will feel it most during acceleration or highway passing. Both reduce overall engine efficiency and fuel economy.
Can the IMRC system cause an engine to run rich or lean?
Yes. Abnormal airflow through the intake runners can disrupt the air/fuel mixture. You may see associated oxygen sensor codes or fuel trim codes alongside P2006 on high-mileage engines with significant carbon buildup.
How can I prevent IMRC carbon fouling?
Use Top Tier certified gasoline, which contains more detergent additives. Periodic intake cleaning with a product like BG 44K or Sea Foam added to the fuel is also effective. Ocasional hard acceleration (safely on a highway on-ramp) helps burn off minor deposits.