I'm not sure about every model, but with some, disconnecting the battery
does not clear the error codes. The OBDII tool has to send a reset
command to the controller.

P0102 could mean that there is inadequate flow through the MAF,
possibly due to a restriction inside it, an engine vacuum leak, etc.
Assuming you didn't get a bad MAF out of the box, you could check the
electrical basics as well.  Your MAF generates a frequency, not a
varying voltage, so your bench testing method was probably flawed.

First, check the pink wire for full battery+ voltage.  Then check the
Black/White wire for ground.  Finally, test the yellow wire with engine
idling and MAF connected: backprobe the yellow wire with positive lead,
ground the neg lead, and set your DVOM to read frequency.  You should
see about 3000 Hz at idle.  Below a certain threshold (about 1000 Hz)
the PCM will flag a code P0102.  If the freqency is good at the sensor,
it should be good at the PCM given the 5v. reference circuit design
used.  This is where an oscilloscope would better show how clean the
signal is and the low and high voltage points, but if you don't have a
scope this sentence is academic.

Toyota MDT in MO

vacuum leak

Hi all,

Thanks for the good advice.  I was finally able to get the error codes
cleared.  I tried disconnecting both positive AND negative battery cables.
Previously I had just disconnected positive cable and let the car sit for
about 15 minutes.  Upon reconnecting and starting up, the check engine light
finally stayed off.  Not sure if it was a matter of both cables being
disconnected, or I had read that some models require three good starts
before self clearing a condition code.

Jason