P0411: AIR System A Incorrect Flow Detected
A generic powertrain (engine and transmission) trouble code, same meaning on every brand.
Yes - no effect outside the first minute of cold running.
Symptoms
- Check engine light
- Cold-start emissions smell stronger
- No warm-engine symptoms at all
Likely causes, most common first
- Air path blocked - hoses, passages or a stuck combination valve
- Pump weak but running
- Check valve stuck closed
- Leak between pump and exhaust
Read P0411 yourself before paying for diagnosis
A basic Bluetooth OBD-II scanner ($20-40) plugs into the port under the dashboard and shows this code with live sensor data on your phone - useful both for confirming the fix and for talking to a shop from an informed position.
What is going on and how it gets diagnosed
P0411 is more specific than P0410: the pump runs, but the oxygen sensors do not see the extra air arriving in the exhaust. Air is being made and lost, or not moving at all.
Carbon gradually closes the small passages that feed air into the exhaust ports - a known pattern on several German engines, where the repair is cleaning the passages rather than replacing hardware. Listen first, though: if the pump audibly runs after a cold start, the pump is innocent and the fault is downstream of it in the valves and passages.
Repair options and cost
Typical US independent-shop ranges, parts and labor. Dealers run higher; regional labor rates vary.
Owner reports mentioning P0411
“Clogged manifold and engine head. Blockage buildup in manifold and Pcv valve causing exhaust problems. Oil sludge block air in head and manifold causing CEL to come on. And these vehicles drink engine oil like water. Gives code P0411”2015 GMC Terrain · Jan 2025
“The exhaust manifold cracked and failed. The failed part was not retained by the Chevrolet dealer repair shop. A safety issue arose as exhaust gases entered the passenger compartment via the vehicle's air circulation system. The failure of the exhaust manifold was confirmed by the dealer and replaced at considerable cost (i.e., $2200). No other parties inspected the failed part. There was a check engine light illuminated on the dashboard. The dealer retrieved a P0411 diagnostic trouble code and believed that it was related to the exhaust manifold leak. The exhaust manifold leak first appeared on November 1, 2023.”2013 Chevrolet Equinox · Nov 2023
“2015 Chevy Equinox DTC Error code P0411.SAI ports should be cleaned or replaced. Front sway bars malfunctioned and needs replaced.Please see if this is covered under warranty vehicle is only 8 years old only had it for 3 years.”2015 Chevrolet Equinox · May 2023
Show 4 more owner reports
“Codes p0411 & p2440 detected after diagnostics, pump supplies catalytic converter for purpose of reducing harmful emissions. Both converters were replaced under warranty this year. Why is a.I.r. Not covered if it is related to the converters? Engine light on .”2014 Chevrolet Cruze · Nov 2018 · 73,000 mi
“Code p1410 secondary air injection system switching valve stuck open. This is a common error many 2006 and up subaru impreza wrx owners are having. The emissions system is prone to fail due to carbon buildup or moisture and rust contaminating valves, leading to repairs costing $700 to $1500. This failure is common even with low mileage. Note these codes are also associated with this failure: 06/07 wrx: p0410 p0411 p0413 p0414 p0416 p0417 p0418 p2431 p2432 p2433 p2440 p2441 p2442 p2443 p2444 07 sti: p0410 p0411 p0413 p0414 p0418 p2431 p2432 p2433 p2441 p2444 *tr”2006 Subaru WRX · Jan 2012 · 66,870 mi
“Code p1410 secondary air injection system switching valve stuck open. This is a common error many 2006 and up subaru impreza wrx owners are having. The emissions system is prone to fail due to carbon buildup or moisture and rust contaminating valves, leading to repairs costing $700 to $1500. This failure is common even with low mileage. Note these codes are also associated with this failure: 06/07 wrx: p0410 p0411 p0413 p0414 p0416 p0417 p0418 p2431 p2432 p2433 p2440 p2441 p2442 p2443 p2444 07 sti: p0410 p0411 p0413 p0414 p0418 p2431 p2432 p2433 p2441 p2444. *tr”2006 Subaru Impreza · Apr 2011 · 60,000 mi
“I have had numerous troubles with the control module having codes in it. Right now, I have a p0411 code, secondary air flow. The ecm has been replaced already, leading me to believe that there's trouble for me down the road!*ak”2001 Volkswagen Jetta · Mar 2004 · 44,000 mi
Cars that report P0411 most often
Based on mentions of this code in NHTSA owner complaints.
Frequently asked questions
Can I drive with P0411?
Yes - no effect outside the first minute of cold running.
How much does it cost to fix P0411?
Typical US repair costs range from $100 for the simplest fix (hose or valve replacement) to $800 in the worst case. The right number depends on which cause your car has - see the causes list.
Related codes
The codes closest to P0411. They often appear together, and telling them apart is usually what narrows the diagnosis.
Definition per SAE J2012 standard nomenclature. Symptoms, causes and costs are editorial guidance - always confirm with a diagnosis of your specific vehicle.