Q: Check engine light, EGR.

Hello. Thank you for writing in. The issue you are having may not be directly related to the EGR valve, but may pertain to the passages around it. Carbon build up in the passages around the EGR valve will inhibit the flow of exhaust gases that are being recirculated into the intake. These can be cleaned by hand with a number of chemicals on the market after removing necessary components to access them. With those properly cleaned, you will want to reinstall the EGR valve. At this point make sure that your connections are clean, dry, and tight. The other issue is that the valves often release extra exhaust into the system when they shouldn’t be, however this should have been resolved with a new unit and seals. Make sure that the unit’s manifold is not damaged as well. Clean the EGR valve’s passages, and make sure the new unit is installed correctly.