You will be able to drive with it malfunctioning, but your emissions will be way out of acceptable levels, the reason why is that.
The Exhaust Gas Recirculation (EGR) valve sends some of the exhaust gas back into the cylinders to reduce combustion temperature. This is required because nitrous oxides (nasty pollutants) form when the combustion temperature gets above 2,500 degrees F. This is as a result of the formation of nitrous oxides when the nitrogen in the air mixes with the oxygen. When it s sunny, the nitrous oxides from the exhaust get together with the hydrocarbons in the air to form smog. This is when the EGR valve comes in handy. By recirculating some of the exhaust gas back through the intake manifold to the cylinders, we can lower the combustion temperature. Lowering the combustion temperature lowers the amount of nitrous oxide produced. Consequently, less of it comes out the tail pipe.
Sunday, December 30th, 2007 AT 11:33 PM