There are a bunch of conditions listed under the fault code, turned out to be none of them.
Had the Engine light for several years without affecting the driving. Changed the EGR valve and used system cleaners. Also took off inspected and cleaned the hose for cracks and holes. Annual inspection for this age of vehicle is not a fail but had to refer examiners to the testing manual for the age qualification. Code reset works for first three miles so that's also got me through.
So combined with a P0488 EGR Throttle performance fault went back in for service. The throttle actuator was burnt out, replaced with a new Throttle Body, while about it also put on another EGR valve.
Throttle fault cleared, EGR not. Turned out the vacuum plug was not sealing enough - fixed with a zip-tie for snugness!