I spent the day at a seminar for auto shop teachers today. One of the sessions was on monitor actuation for all manufacturers. Of course, all I was interested in was the Toyota content, specifically the EGR monitor on the LCs. This is what it takes for the PCM to look at the EGR info, also known as the ERG monitor Drive Trace for all models 96-2002 Pre-Conditioning Requirements MIL must be off Altitude is below 7801 feet (2400 m) IAT (Intake Air Temp) must be above 13*F (-10*C) 1996-2000 LC/LX 450 Engine Coolant Temp must be below 104*F (40* c) Driving Procedure Drive vehicle at a steady speed between 43 and 56 mph for three to five minutes Do not exceed 30% throttle opening maintain smooth throttle inputs Stop the vehicle and idle the engine for 3-5 minutes Rinse and repeat The monitor will store a pending code the first time it fails. The second time it will light the MIL So all you have to do to never have a P0401 is to never drive between 43 and 56 longer than 3 minutes below 30% throttle opening. No problem. All hail Gumby, solver of the impossible.