DTC P0401 - EGR System Insufficient Flow
Perform PCM reset procedure. See TESTS W/CODES - INTRODUCTION article. Connect SCS Service Connector (07PAZ-0110100 ). Test drive vehicle without any electrical load. Decelerate vehicle from 55 MPH for at least 5 seconds. If DTC P0401 is not indicated, problem is intermittent. System is okay at this time. If DTC P0401 is indicated, clean intake manifold EGR port with carburetor cleaner. Clean passage inside EGR valve with carburetor cleaner or replace valve.