P0401 means the EGR (Exhaust Gas Recirculation) valve is not flowing enough exhaust gas back into the intake manifold. The EGR system reduces nitrogen oxide emissions by diluting the intake charge with inert exhaust gas. Carbon buildup is the most common cause, especially on diesel engines.
DTC/P0401·Toyota
P0401 on Toyota: Causes, Symptoms and Fix Cost
Quick Answer
Low SeveritySafe to drive (short-term)Toyota
P0401 on a Toyota means the EGR (Exhaust Gas Recirculation) valve is not flowing enough exhaust gas back into the intake manifold. The EGR system reduces nitrogen oxide emissions by diluting the intake charge with inert exhaust gas. Carbon buildup is the most common cause, especially on diesel engines.
Repair cost on Toyota€8 - €550
What does P0401 mean on a Toyota?
Toyota Camry
2007-2024The Camry's EGR system is relatively simple and reliable. P0401 is uncommon before 150,000 km. When it does appear, cleaning the EGR valve and passages usually resolves it. The EGR valve is accessible on both the 2AR-FE and 2GR-FE engines.
What causes P0401 on a Toyota?
Beyond the generic causes listed on the main P0401 page, these are the Toyota-specific patterns we see most often:
Toyota CamryCarbon buildup at 150,000+ km on petrol engines
Toyota CamryEGR passage restriction in intake manifold on high-mileage vehicles
How to diagnose P0401 on a Toyota with OBD2
Follow these steps to pinpoint the root cause of P0401:
- Check if the EGR valve is mechanically stuck by removing it and inspecting for heavy carbon deposits
- Test EGR valve operation: apply vacuum (vacuum-operated) or command open with scan tool (electronic). The valve should open and the engine should stumble or stall
- If the valve opens correctly, check the EGR passages in the intake manifold for carbon blockage
- On DPFE-equipped vehicles (many Fords), test the DPFE sensor and its hoses for cracks or blockage
- On diesel engines, inspect the EGR cooler for blockage or internal leaks
- Check vacuum supply hoses on vacuum-operated EGR systems for cracks or disconnection
How much does P0401 cost to fix on a Toyota? (EUR)
Estimated repair costs on a Toyota (Toyota costs align with the average for this code across makes).
Prices estimated as of May 2026. Costs vary by region, vehicle, and shop.
Related codes that often appear with P0401 on Toyota
These codes commonly cluster with P0401 on Toyota vehicles:
FAQ: P0401 on Toyota
Can I drive with P0401?
Yes. The EGR system is emissions-related only. You may notice slightly rougher idle, and the car will fail emissions testing. Some vehicles limit power with EGR faults.
Can I clean the EGR valve instead of replacing?
Yes, try cleaning first. Carbon buildup is the most common cause. Removal, soaking in EGR cleaner, and manual cleaning works on many valves. If the valve mechanism is damaged, replacement is needed.
Why do diesel engines get P0401 more often?
Diesel combustion produces much more soot. This carbon passes through the EGR system and clogs the valve and passages faster. Diesel EGR may need cleaning every 60,000-100,000 km.
Is EGR delete legal?
No, in most countries. It increases nitrogen oxide emissions, triggers permanent check engine lights, fails emissions tests, and can result in vehicle deregistration in some EU countries.
Looking for the full P0401 reference (all makes, full diagnosis flow, complete repair cost matrix)?
See the main P0401 guideSkanyx · Toyota
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