85-91 EGR CONTROL VALVE RELAY SOLENOID

Description

The EGR system is meant to reduce smog by reintroducing spent exhaust gases back into the combustion chamber to reduce oxides of nitrogen. The EGR valve on 85-90 Corvettes is opened and closed by the EGR Control Valve Relay Solenoid(GM’s name). This part is also known as the EGR Relay, EGR Solenoid and EGR Switch. The solenoid fails at a much higher rate than the EGR valve and typically causes your C4 to stall, experience rough idle, engine knock and surging or hesitation during acceleration. Before replacing be sure and remove the EGR valve and make sure there are no carbon deposits on the valve. If it is clean or if you clean off the deposits then it is generally safe to assume your Corvette’s problem is the EGR solenoid. If you have a scan tool that reads a code 32 then you know you have an EGR system failure. Further electrical testing at this point can identify the switch as the culprit. If you are unsure of the diagnosis it is suggested you visit a mechanic as the solenoid is a NON-returnable item.