I have to take my 97 Taurus 3.0 Vulcan, 112K miles with OBD II diagnostics
in soon for its first emission test under the new CT emissions test system.
Does anyone know how this car is tested? Do they put it on a dyno with an
exhaust gas analyzer like the old state run system did? Or do they just
read the codes on OBD II? I currently am showing no codes and no check
engine light but I have periodically had spurious P420 codes (Low converter
efficiency bank 1) pop up every few months or so. Someone told me that if
you have had a code reset within a certain number of OBDII test cycles they
will read that from the OBDII and that will cause you to flunk. And what
the OBD says goes, no backup verification with the dyno and gas analyzer.
Anyone know the specifics? I have read that the P420 code is very common on
higher mileage cars but when tested on a dyno with gas analysis, most of
them still pass with flying colors. I believe the spurious P420s I am
getting may be due to RF interference from my amatuer radio mobile
installation. It seems that the spurious check engine lights from P420 I
get are usually coincident with transmitter operation.