OBD code 0401 (1997 Toyota Camry 4 cyl)

A common problem for egr failures are the modulator valves, the valve is attached directly to the egr valve, it's a round plastic housing with three vacuum lines on it, try replacing this valve.

First did you reset the computer after replacing the EGR valve if you don't the computer doe'nt reconize the new sensor so it doe'nt reset the peremiters.Then check all passages and lines in the intake manifold there could be a clogg somewhere.Go to www.rockauto.com and you'll find EGR pressure sensor for under $30.00.

A code P0400 may mean that one or more of the following has happened:
• Plugged EGR passage which restricts the flow of exhaust gasses
• Faulty EGR solenoid
• Faulty EGR solenoid wiring/harness
• Vacuum lines damaged/disconnected to the EGR valve solenoid or to the EGR valve
• Faulty EGR valve

REPLACE THE EGR VALVE ASSEMBLY !

P0401 OBD-II Trouble Code
Insufficient EGR Flow
What does that mean?
EGR stands for Exhaust Gas Recirculation. It is part of the vehicle emmissions system, and is used to reduce combustion temperature and pressure to control Oxides of Nitrogen. There are generally three parts to the EGR system: the EGR valve, an actuator solenoid, and a differential pressure sensor (DPF). These things work together to deliver the correct amount of recirculation based on engine temperature, load, etc. The P0401 code means that OBD detected an insufficient amount of EGR.

It's a valve not a sensor.
Where? it depends what engine do you have 4 cyl 6 cyl?
How do you know the EGR valve could be bad? check engine light on? OBD code? diagnostic made?
Help us to help you please provide more information
Hope it will help
Dan

how I change the EGR valve assist switch for toyota camry 2000

Go to Autozone and have your current EGR Valve, removed from the car, tested and they will determine if it is defective. They tested 2 for me, and neither was a replace, just a clean and they worked great. If they don't have a brand that suits your wants, just test it, then buy the new somewhere else, no commitment to buy.
The most common problem with these EGR valves is they get plugged up from carbon build up. Best way to test it is with a little hand held vacuum pump. Hook it up to the EGR valve and with the engine running at idle and squeeze the vacc pump handle a couple times to open the EGR valve. That should kill the engine. If it dosent, the EGR valve is probably plugged up. At that point you'll have to take it off and clean the carbon out. Even if you have your mechanic check into it, it shouldnt be that expensive to remove it and clean it out or replace it.

Good Luck and hope this helps: Oh and I think theres two EGR.. check the one on the bottom of the engine to. I am not sure but i think there are two EGR valves on your camery.  

hello, to fix this problem what you need to do is replace your egr valve its a pretty straight forward replacement ,to get a new one goto any auto parts store and tell them what you need thay all carry egr valvs in stock cost is about 30.00$

replace the EGR switching valve and have the machanic clear the engine check light. I think it should help