A person of the extra typical codes that I ordinarily see on a 1997-2001 Toyota 2.2L 4-cylinder Camry is a P0401. It is a code that signifies that there is a trouble with the EGR Program, not necessarily a challenge the EGR valve itself. I listen to tales of people today pulling finding this code and replacing the EGR Valve with no doing any screening since they really don’t know what to exam. They devote needless income and nonetheless have not mounted the difficulty.
There are a few areas that will commonly make this code surface on your vehicle. Indeed the EGR Valve is one particular of them, but you also have the EGR VSV, and the EGR Modulator. The to start with pieces of inspection will be to check the purpose of the EGR Valve by pulling a vacuum on it with a vacuum pump. You can get a vacuum pump at and car components keep for close to $20 and even lease just one at some stores.
Hook up the pump to the only vacuum port on your EGR valve. There will be a tiny hose connected, that you will require to disconnect and set up your pump on to the very same port. With the engine functioning at an idle you ought to be capable to pump the vacuum pump to make vacuum on the EGR valve. The diaphragm inside the EGR Valve need to elevate and bring about the auto to die. If your automobile does die then your EGR Valve and it can be ports are fantastic. If your vehicle stumbles or isn’t going to have any adjust in the way it runs when you happen to be pulling vacuum then you in all probability have a bad EGR Valve or a clogged port in your intake.
If you feel you have a lousy valve then you ought to just take it off the motor and exam it with the same vacuum pump. You need to be equipped to see the diaphragm within the valve move as you are applying vacuum. If the diaphragm does go then you could have clogged ports in your intake and may well will need to have the intake cleaned. If it will not transfer then you need to exchange the EGR Valve.
Nevertheless, if your Camry stopped operating when you utilized that to start with vacuum then you ought to start looking to the EGR VSV. I know VS what? It truly is a smaller blue solenoid situated on the again of the engine block. It will have a pair of vacuum hoses, and a modest plug hooked up all be held up there with just one 10-mm bolt. Take out the VSV and check it by applying power and ground from your autos battery (VSV must not be plugged into harness when tests.) If you listen to the VSV click when you use energy then you should swap the EGR Modulator.
The EGR Modulator is positioned to the suitable of the EGR Valve previously mentioned your intake. It will have numerous vacuum hoses coming off of it and slides into a holder. The EGR Modulator can be purchased somewhat low cost at your seller. There is no simple screening for the modulator. If you replace the modulator and still have a dilemma and the light-weight arrives back again on, you ought to then swap the EGR VSV also recognised as the Vacuum Switching Valve. Occasionally the VSV can have an internal crack and even now click when you set electricity and floor to the terminals, but nonetheless be negative.
So you could be squandering your revenue by just throwing on a valve. Try to remember the only way to repair some thing right is to know the right screening procedure so you can appear to a proper repair.
