Dredging from the grave....
Just FYI and thanks to everyone for their help. Swapping out the O2 sensor brought down the HC to passing levels, but the CO was about double the limit. (I ohm'ed the sensor, and it looked like the heater element must have died in it. So a Bosch lasts about 2 years....). I then swapped out the cat, and wow, what a diff.
HC - 101ppm (limit 220ppm)
CO - .347% (limit 1%)
The CO was over at idle, but the 2nd idle (2500) passed, so they said the cat probably got cold while waiting. So now this rig is back on the road...
Just FYI and thanks to everyone for their help. Swapping out the O2 sensor brought down the HC to passing levels, but the CO was about double the limit. (I ohm'ed the sensor, and it looked like the heater element must have died in it. So a Bosch lasts about 2 years....). I then swapped out the cat, and wow, what a diff.
HC - 101ppm (limit 220ppm)
CO - .347% (limit 1%)
The CO was over at idle, but the 2nd idle (2500) passed, so they said the cat probably got cold while waiting. So now this rig is back on the road...