Hi, I have multiple EGR codes including insufficient flow, fuel is too lean, one or the catalytic convertor and one other. I've had the EGR Valve, Valve Sensor, Vacuum Control Switch, and EGR Solenoid Replaced but the light keeps coming back on. Usually the car also idles very rough. I've taken it to multiple locations with no solution. I've also had the intake manifold gasket replaced recently, along with an 02 sensor and spark plugs.
I had the catalytic convertor checked out and the guy said he doubts that's it. No vacuum leak has been detected and checked for carbon build up in the intake.
Any ideas before taking it to the dealer?