Eng Malfunction Light keeps coming on from time to time. I replaced the lower O2 Sensor about a year ago.
It comes on from time to time for a day or two and then goes off. However, its now been on for two weeks. I had AutoZone clear all of the codes and it came back on within a day.
Had it read again this moring:
P0420
Catalyst system efficiency below threshold bank 1
Probable Cause:
aa1 A/F ration concern
aa2 Air leak near HO2S (heated Oxygen sensor) bank 1
aa3- ignition system concern
aa4- faulty catalytic converter
Not sure where to go. Like I said, I did the O2 Sensor about a year ago and within 3-4 months the light was coming back on for a day or two.
It comes on from time to time for a day or two and then goes off. However, its now been on for two weeks. I had AutoZone clear all of the codes and it came back on within a day.
Had it read again this moring:
P0420
Catalyst system efficiency below threshold bank 1
Probable Cause:
aa1 A/F ration concern
aa2 Air leak near HO2S (heated Oxygen sensor) bank 1
aa3- ignition system concern
aa4- faulty catalytic converter
Not sure where to go. Like I said, I did the O2 Sensor about a year ago and within 3-4 months the light was coming back on for a day or two.
Jan 18, 2010 at 1:35 AM
