EGR valve ? ?

[michoujordan76]

Hi All,

The check engine light in my 91 Camry comes on from time to time so I took it to the dealer. They said that it is caused by the EGR valve and that it's not worth changing given the age of my car.

I like my car and would rather keep it in good running order than wait for it to die from neglect. So, what does this EGR thing do and should I fix it?

Plus this car is originally from California; can I use a regular part or will that cause a problem?

Thanks for your help!

[Doctor J]

The EGR valve is used to meter small amount of exhaust gases back into intake manifold during slow acceleration or steady cruising speed. The purpose of EGR is to lower combustion temperature by diluting the mixture. As a result of lower temperature, the Oxides of Nitrogen are forming in much smaller amounts then without EGR. In addition, use of EGR system allow to use regular grade gas without detonation and/or pre-ignition. However, the intake charge dilution lowers the power output and fuel economy.
The system on your car consists of EGR valve, vacuum modulator (aka back pressure sensor), bi-metal vacuum switching valve and vacuum hose. Starting 1989, the thermistor is screwed into the EGR valve, that sends the analog signal to the computer,and if EGR gas flow is low due to the valve or passage restriction, the temperature will also be low, therefore computer will set code 71.(Make sure that this code is displayed)
The most common EGR problems:

• defective vacuum hoses
• carbon blocking valve-to-intake manifold passage - remove and clean
• ruptured diaphragm in the modulator
• broken off vacuum switching valve
• plugged vacuum signal ports in the throttle body

[toyomoho]

Could be carbon build up, owners have had success at removing the valve and cleaning it. Getting a California part should not be a problem, check costs first. One reason to clean the valve if possible.

[fredk]

simply put a bolt in the vacuum line that goes to the valve and be done with it, ive done this to all mine, if it pings, just back the timing up slightly, your mpg will go up too

[michoujordan76]

Thanks for all the detailed help.

I read on the web that a faulty egr valve can cause rough idle and stifled acceleration.

What say you?

[Doctor J]

If EGR stays partially open due to internal corrosion, the answer is yes
If the recirculation never take place due to plugged valve or passage, the car will actually get better accelerating power and fuel economy, but may ping due to higher combustion temperature.

[IvanHoe]

Originally Posted by fredk

simply put a bolt in the vacuum line that goes to the valve and be done with it, ive done this to all mine, if it pings, just back the timing up slightly, your mpg will go up too

Do you have any pics?, Id love to do this!

[marc780]

Junkyard part is an option. Smog check is tough here so blocking it wouldnt work for me - if no smog where you live, id try and do what fred said, for a temporary fix,