EGR System in Toyota Camry

toyota
camry

#1

Recently the check engine light came on our 2001 Camry, had the computer checked and it was a malfunction in the EGR System? After checking with other Camry owners, this is appears to be a common occurance. I’m curious if others have had this problem and what the have done about it, if anything?? Can someone explain the EGR system for the layman to understand?


#2

EGR=Exhaust Gas Recycle. It’s a subsystem that routes some exhaust gas back into the intake manifold in order to reduce the percentage of Oxygen in the fuel mix. That discourages the formation of Nitrous Oxide when the engine runs. See http://en.wikipedia.org/wiki/Exhaust_gas_recirculation

There’s an EGR valve that causes the EGR system to kick in when the car is warm and running at speed, and shuts it down when the car is cold or idling.

On many cars, there can be EGR problems as the car ages. Either the gas passages may plug up with carbon, or the EGR valve may stick, or the valves that control the EGR valve may fail. If an EGR valve sticks open, the car will probably idle roughly and may stall sitting at lights or such. If it sticks closed the engine may run a bit warm, but you probably won’t notice.

Fixing EGR problems isn’t usually terribly expensive. A few hundred dollars typically. If you’re handy with tools, EGR repair isn’t usually horribly complex, but like a lot of auto repair jobs, it could go wrong and turn into a nightmare, if – for example – a difficult to reach bolt shears off.


#3

The EGR valve intentionally reduces the efficiency of the engine so it produces less NOx. It ONLY opens during steady state cruising. It is closed virtually all the rest of the time.

If you must pass an emissions test, the CEL must be cleared and stay cleared during the “test”…Other than that, EGR faults can be ignored.

As a DIY project, you can locate and remove the valve, clean it up and make sure it is working freely and “rod out” the exhaust gas passages that the valve controls with a coat hanger in an attempt to restore EGR flow…