I have a P0401 code that won't seem to go away.
2000 GTP, 94K Miles, No Mods. Car is running as good now as it ever has except for the SES light.
I have searched numerous internet postings and have tried a lot of the things that has been recommended. The following have been fixed / replace / cleaned so far: New EGR Valve, New MAP Sensor, New PCV Valve, Cleaned hose from EGR to intake manifold, cleaned throttle body, new O2 Sensor and repaired leak in exhaust. The repair shop has done some preliminary diagnostics and found that the EGR is functioning. They want it back to do a deeper diagnosis. Does anyone have any further suggestions before I take it in. I have heard that it may require a re-flash in order to get rid of the SES light.
