Just one of the a lot more popular codes that I commonly see on a 1997-2001 Toyota 2.2L 4-cylinder Camry is a P0401. It is a code that signifies that there is a difficulty with the EGR System, not essentially a difficulty the EGR valve alone. I hear stories of persons pulling obtaining this code and changing the EGR Valve without the need of executing any screening for the reason that they don’t know what to exam. They spend needless cash and continue to haven’t fastened the issue.
There are a few pieces that will usually make this code look on your vehicle. Of course the EGR Valve is a person of them, but you also have the EGR VSV, and the EGR Modulator. The first parts of inspection will be to examine the perform of the EGR Valve by pulling a vacuum on it with a vacuum pump. You can get a vacuum pump at and auto pieces retail store for all around $20 and even hire just one at some suppliers.
Hook up the pump to the only vacuum port on your EGR valve. There will be a compact hose connected, that you will need to disconnect and set up your pump on to the identical port. With the engine operating at an idle you need to be in a position to pump the vacuum pump to create vacuum on the EGR valve. The diaphragm within the EGR Valve must increase and result in the auto to die. If your automobile does die then your EGR Valve and it truly is ports are high-quality. If your auto stumbles or isn’t going to have any transform in the way it operates when you might be pulling vacuum then you in all probability have a terrible EGR Valve or a clogged port in your ingestion.
If you assume you have a poor valve then you should acquire it off the motor and take a look at it with the exact vacuum pump. You should be equipped to see the diaphragm within the valve shift as you are applying vacuum. If the diaphragm does shift then you could have clogged ports in your ingestion and may possibly need to have the ingestion cleaned. If it does not transfer then you should swap the EGR Valve.
Having said that, if your Camry stopped managing when you used that initially vacuum then you should really start on the lookout to the EGR VSV. I know VS what? It truly is a small blue solenoid found on the back again of the engine block. It will have a pair of vacuum hoses, and a tiny plug attached all be held up there with 1 10-mm bolt. Take out the VSV and test it by implementing electric power and floor from your vehicles battery (VSV ought to not be plugged into harness when tests.) If you hear the VSV simply click when you utilize power then you must replace the EGR Modulator.
The EGR Modulator is located to the ideal of the EGR Valve earlier mentioned your ingestion. It will have numerous vacuum hoses coming off of it and slides into a holder. The EGR Modulator can be ordered rather affordable at your seller. There is no easy testing for the modulator. If you replace the modulator and nevertheless have a challenge and the gentle comes back again on, you should really then replace the EGR VSV also acknowledged as the Vacuum Switching Valve. From time to time the VSV can have an internal break and still simply click when you set electricity and ground to the terminals, but even now be undesirable.
So you could be throwing away your dollars by just throwing on a valve. Don’t forget the only way to deal with something right is to know the proper tests course of action so you can arrive to a correct repair.