I am having a similar problem. I just moved to NY where they check
the OBD for emissions testing. I registered my car, 2000 Sonata GLS,
and had 10 days to get the inspection done. Two days before my
appointment the MIL comes on right at start up . I drove home and had
it read the next day. P0705, P1154, and P0153. Clear the codes and
drive about 100 miles with no MIL before the inspection. At the
inspection they tell me its not ready and to drive it some more.
After another 200 miles and still not being ready, I started digging
in. At idle in my garage for 1 hour and it never went into Closed
Loop. I was using a generic reader and found online that there is a
Hyundai specific code for not going closed loop, so I couldn't see
that, but it didn't light the MIL. I noticed the B2S1 sensor didn't
look like it was going high enough so I replaced that with a Bosch
from NAPA. Now the car goes into closed loop right away but after
another 200 miles it still won't run the O2 sensor test. The EVAP,
Heated O2, misfire, fuel system, and comprehensive are all ready, the
MIL is off and there are no generic codes showing. CAT of course
hasn't run yet. Could there be a pending code stuck in there related
to the Open Loop condition I was running in that didn't light the MIL
but is preventing the O2 test from running? Both upstream O2 sensors
now switch between 0.1 and 0.9V however, for whatever amount of time
the scanner screenshot is, the Bosch will cycle 4 times and the other
upstream sensor 7 times. Is this a problem that they aren't the
same? I'm not sure how accurate the waveform is in the program but
the rise and fall times look similar, the Bosch just stays high and
low longer. I did have both sensors replaced and the reprogramming
done back in 03.
I'm assuming I may need to replace the transmission range sensor
switch in the near future but didn't think it relates to the O2 sensor
problem and the MIL hasn't come back on yet so I'm not worrying about
it for now.
>> Stay informed about: Will not pass Smog test after new battery