Economy and low emissions are the name of the game for the 2003 Honda Civic. To provide the lowest emissions, all of the Civic's emission controls must operate correctly. This includes the exhaust gas recirculation valve. This valve opens to allow a small portion of the exhaust gases back into the combustion chamber to burn off nitrogen oxide before it exits the tailpipe.
The short answer is yes, the 2003 Civic LX does have an EGR valve. It is on the passenger side of the valve cover, near the middle of the engine compartment. The EGR valve connects to the rest of the Civic's wiring by way of a five-pin wiring harness.
There are five diagnostic codes that relate directly back to the EGR valve: P0401, P0404, P0406, P1491 and P1498. These codes may not mean that the EGR valve itself has failed. Broken wiring, shorts, computer failure, clogged EGR tubing and other related failures may trigger these codes as well. A full diagnostic on the EGR system will expose the exact cause of your Civic's EGR system issues.
