What P0410 means
After a cold start the secondary air (AIR) pump blows fresh air behind the exhaust valves so that unburnt fuel burns off and the catalyst heats up faster; a shut-off valve opens the path and stops exhaust from flowing back.
How the engine computer detects it
P0410 is the general function code for secondary air system A. Many Bosch-managed engines check it passively: with the pump running, the front oxygen sensor must read lean or the fuel control must react; Pierburg lists P0410 as no lean signal, i.e. no air detected. Saab's Motronic 900, by contrast, uses it for too much air. GM's systems with a pressure sensor use P0411 and P2440 ff instead. The check runs once per trip after a cold start; driving is unaffected.
Written from public technical sources and not yet checked by a mechanic. How we write these pages
Symptoms
- Check engine light on
- Secondary air readiness not set (emission test)
- Pump silent after a cold start, or unusually loud
- Driving normal, higher cold-start emissions
Common causes
- Secondary air pump failed (water ingress, seized) Most likely
- Combination or shut-off valve carboned up or stuck Most likely
- Vacuum hose or electric changeover valve leaking or faulty Possible
- Pump relay or fuse faulty Possible
- Air ducts in the head carboned up or hose off Possible
How to diagnose P0410
- Read every stored code with an OBD-II scanner. If misfire or fuel trim codes are there too, fix those first: they often cause this one.
- Inspect the parts involved: secondary air pump, air combination valve, air pump relay, front oxygen sensor.
- Work through the causes above from most to least likely, cheapest checks first.
- Clear the code and drive a full drive cycle to confirm the repair held.
Vehicles that report P0410 most
| Vehicle | Years | Reports | Share | Median miles |
|---|---|---|---|---|
| Subaru Impreza | 2006–2014 | 3 | — |
Counts of owner complaints to the NHTSA that mention P0410 (11 in total), not failure rates: popular models get more complaints simply because more of them are on the road. Models with fewer than 3 complaints are left out.
Reading the code
- P
- Powertrain
- 0
- Generic (SAE) code
- 4
- Auxiliary emission controls
- 10
- Specific fault
Questions drivers ask
Can I drive with code P0410?
Usually yes for a short time, if the car drives normally, the temperature gauge reads normal and the check engine light is steady. If the light flashes, the engine loses power or overheats, or other warning lights come on, pull over and have it checked.
Will my car pass an emissions inspection with P0410?
Probably not in states that test vehicles with an OBD-II scan: an emissions-related code that keeps the check engine light on is usually an automatic fail. Rules differ by state and county, so check yours.
Will P0410 clear by itself?
The light can go off after several drive cycles without the fault, but the code returns if the cause is still there. After a repair, the readiness monitors need a full drive cycle before an inspection.
Can I fix P0410 myself?
Often yes, with an OBD-II scanner and basic tools. Difficulty: medium. Start with the cheapest checks before replacing expensive parts.
Often reported together
Codes that owners mention in the same NHTSA complaints as P0410. They can point to a shared cause, so it's worth checking them together.
- P2440Secondary Air Injection System Switching Valve Stuck Open (Bank 1)4 complaints
- P2444Secondary Air Injection System Pump Stuck Off (Bank 1)3 complaints
This page is general information, not a substitute for a professional diagnosis. Repair costs are rough estimates for parts and labor and vary by vehicle and region.