Our 2002 Dodge Grand Caravan is due for NJ State Inspection this
month, and in keeping with Murphy's legacy, our "check engine" light
decided to appear a week ago. Using the key on-off sequence, the
failure code was a P0456, or small evaporative emissions control system
leak. Researching the situation, I found reports about this occurring
via a loose fitting or failed gas cap. We have been wanting a locking
gas cap anyway, so I replaced same, but neither the "check engine" nor
the P0456 failure code disappeared after several engine cycles. Not
knowing at this point as to whether the problem had been solved or
whether the PCM was taking its time resetting, I purchased an Actron
9135 scan tool and reset the P0456 failure code.

After resetting the code, four of the I/M parameters went to "NOT
READY" (CATALYST, EVAP SYS, O2 SENSOR, and HO2 SENSOR). After 50+ miles
of driving with several engine cold-hot cycles, the "check engine light
has not reappeared, and three of the above I/M parameters have gone back
to "READY", but the HO2 SENSOR parameter remains at "NOT READY".

Does anyone have any info as to how long this HO2 SENSOR code will
take to reset? I have the factory service manual, but can't find any
info there. If its going to take 30 or 40 engine cycles to reset, I'll
have to just let the car fail inspection, but would rather not go that
route if there is anything I can do to get this parameter back in line.

Thanks in advance for any help!


George